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2022-03-31 | Background Behçet’s disease (BD) is a multisystem autoinflammatory disease characterised by mucosal ulceration, ocular, neural, joint and skin inflammation. The cause of BD is not known but there is a strong genetic association with HLA-B*51, IL10 and IL23R. Neutrophils are a first line of defence against invading pathogens and have been described as activated in patients with BD. Neutrophils can now be separated into different subsets, such as low density (LDN) and normal density (NDN) that have diverse functional roles. We wished to address neutrophil heterogeneity in patients with BD. Methods Peripheral blood neutrophils were obtained from 32 BD patients and 37 healthy aged-matched controls. Percoll isolation was used to isolate all neutrophils, while Ficol-Hypaque was used to obtain LDN and NDN. Phagocytic capacity and production of reactive oxygen species (ROS), and neutrophil extracellular traps (NET) stimulated with phorbol 12-myristate 13-acetate (PMA) and Escherichia coli ( E.coli ) were assessed in both groups. Results We have demonstrated reduced phagocytic capacity and ROS production but greater NET production by total neutrophils stimulated with PMA or E.coli from BD patients in comparison with healthy controls. Patients with BD had elevated numbers of LDN and lower number of NDN compared with healthy controls. However, both neutrophil subsets showed the same reduced ROS production and phagocytic function as total neutrophils in both groups. Conclusion Our novel findings indicate that the neutrophil population in BD is heterogeneous and the increased number of LDN in combination with greater NET production may contribute to the inflammatory response and pathogenesis. | Low density neutrophils are increased in patients with Behçet’s disease but do not explain differences in neutrophil function | 10.1186/s12950-022-00302-1 |
2022-03-31 | In freshwater ecosystems, flood pulses, the degree of connectivity between environments, and the vegetation mosaic are among the main variables affecting environmental structure at the landscape scale. At a finer scale, local limnological conditions seem to be more important for structuring river fish assemblages. However, rather than exerting isolated effects, these limnological characteristics can have combined impacts on the environment. We evaluated the main drivers of the spatial structuring of fish trophic guilds in the littoral zone of lakes in the Upper Paraná River floodplain (UPRF) and determined the relative importance of limnological conditions, spatial distance, and riparian vegetation. We sampled fish and limnological variables in June, September, and December of 2011, and classified the fish species into trophic guilds. We used variation partitioning analysis to assess the influence of the three sets of predictors and distance-based redundancy analysis to visualize the position of samples, as described by the composition of trophic guilds in multivariate space. The distribution of trophic guilds was mainly influenced by limnological variables, i.e., conductivity, chlorophyll a , and pH, in periods of low water. Spatial and riparian vegetation predictors, despite being low, also influenced the distribution because limnological variables and riparian vegetation of the UPRF have a well-defined spatial structure due to differences between rivers. The lakes with Class III riparian vegetation (dominated by tree species) supported most of the trophic guilds, including insectivores. This indicates that allochthonous materials, even when they occur in smaller proportions, contribute to the structuring of fish communities in periods of low water. | Drivers of fish trophic guild composition in lakes of the Upper Paraná River floodplain | 10.1007/s00027-022-00860-9 |
2022-03-31 | Conventional activated sludge system is confidently widely used for biological treatment plants of municipal wastewater but suffering from operation problems that affect their efficiencies and effluent qualities, especially when treating low-strength wastewater with increasing incoming flow. The objective of this study is to evaluate and compare the novel methods used in upgrading conventional activated sludge treatment systems receiving low-strength wastewater to generate good effluent quality. GPS-X Simulator V 8.0 was used for model calibration and plant performance prediction. The calibrated GPS-X model proved that eliminating primary settling from the treatment process does not affect BOD 5 and COD removal, while TSS removal is decreased, and NH 4 -N removal is increased. Increasing the return activated sludge flow from 50 to 150% of influent flow does not affect conventional activated sludge process, while the change of waste activated flow had a vital effect on process performance. The presence of an anoxic zone in conventional activated sludge processes treating low-strength wastewater has no significant impact on plant performance. Also, the model outputs proved that adding filling media to the aeration tank was able to handle an increase of influent flow and a stable performance of BOD 5 , and NH 4 -N removal was observed. | Applying novel methods in conventional activated sludge plants to treat low-strength wastewater | 10.1007/s10661-022-09968-9 |
2022-03-30 | Background Premature ovarian failure (POF) is a complex heterogeneous disorder characterized by the triad of amenorrhea, hypergonadotropinism, and hypoestrogenism in women before the expected age of menopause. In most POF patients, the etiology is idiopathic. X chromosome abnormalities are known to be responsible for many POF cases but the effect of sex chromosome low level mosaicism on ovarian function still remains unclear. The aim of this study was to investigate the prevalence and type of cytogenetic abnormalities as well as low-level sex chromosome mosaicism in Egyptian females with POF. Results The present study recruited thirty women with POF and thirty women with normal reproductive history as a control group. Conventional cytogenetic analysis was carried out on POF patients in order to detect cytogenetic abnormalities. FISH on interphase and metaphase nuclei from patients with normal karyotype as well as from thirty control women with normal reproductive history was performed using X, Y, and 18 centromeric probes to evaluate low-level sex chromosome mosaicism. Conventional cytogenetic analysis of peripheral blood lymphocytes demonstrated chromosomal aberrations in 7 cases. FISH revealed that the rate of X chromosome mosaicism was significantly higher in POF patients than in the control group. Conclusion We concluded that X chromosome abnormalities including low level mosaicism may be underlying the pathology of POF as increased mosaicism may lead to accelerated oocyte aging and premature follicular atresia. | Cytogenetic abnormalities in a sample of females with premature ovarian failure | 10.1186/s43043-022-00098-3 |
2022-03-29 | Low-strength concrete (LSC) elements are prone to several seismic and static loads and are one of the priorities to be considered for FRP strengthening. However, certain provisions should be taken into account according to provisions, as elements with considerably low compressive strength are not eligible for FRP confinement. This experimental study investigates (1) the effect of rebar planting on increasing the initial compressive strength of LSC to achieve allowable compressive strength for FRP strengthening, and (2) the effect of CFRP confinement on increasing the strength of rebar-embedded specimens and determining the most effective factor for strength improvement. For this purpose, 38 standard concrete cylinders were tested under compressive load. The variables of this study were rebar length and diameter, the compressive strength of concrete, and the number of CFRP sheets. Two initial compressive strengths below the designated compressive strength of 17 MPa (12.5 and 14.5 MPa) were selected. After determining rebar-reinforced specimens with compressive strength of more than 17 MPa, CFRP confinement and compressive tests of these cylinders were utilized. A statistical single-factor ANOVA analysis is performed to determine the most effective variable for ultimate strength and strain, individually. In the end, available models in the literature were utilized to predict experimental data. The results indicated the effectiveness of rebar planting for strength enhancement up to 53%, also showing that specimens with initial compressive strength of 14.77 MPa were suitable for CFRP confinement after rebar planting. The experimental and statistical ANOVA results demonstrated the CFRP confinement and its interaction with rebar embedment as the most effective factors with respect to increasing the load-bearing capacity of LSC concrete. | The Effect of Rebar Embedment and CFRP Confinement on the Compressive Strength of Low-Strength Concrete | 10.1186/s40069-022-00502-2 |
2022-03-28 | In this work, we developed an efficient electrochemical exfoliation strategy for the preparation of graphene (eGr) nanosheets. Newly designed nanosheets-like eGr/GCE electrode possessed large specific surface area, low defect and good electrical conductivity, which facilitates the preconcentration of Kinetin (KT) onto the electrode surface. It exhibits a linear range extending from 0.5 to 100 µM and the lowest detection limit at 0.15 µM. The KT oxidation on eGr is an adsorption-controlled process, which involves a total of 4 H + and 4 e − in the transferring processes. Moreover, there were no significant interfering substances among inorganics (NO 3− , Cu 2+ , K + , PO 4 3− , SO 4 2− , Na + , Cl − ), quercetin, rutin, luteolin, luteoloside, naphthylacetic acid, 2,4-dichlorophenoxyacetic acid and indole-3-acetic acid. The recoveries are in the range of 89.6–117.43% with a relative and deviation (RSD) < 4% ( n = 3) for KT detection in lettuce. | Highly sensitive detection of kinetin with electrochemical exfoliation of graphene nanosheets | 10.1007/s00339-022-05471-7 |
2022-03-27 | The performance of zeolite membrane supports directly determines the synthesis performance and industrial application of zeolite membranes. In this study, a novel and high permeation SiC supports for NaA zeolite membrane were prepared by carrying out in situ reaction bonding at high temperature in the air atmosphere to coat the SiC particles with aluminum sol. The effects of process parameters on the formation of porous structure of SiC supports were systematically investigated, and the underlying mechanism was explored. During the sintering process, high-temperature Al 2 O 3 from aluminum sol reacted with SiO 2 generated by oxidation of the surface of SiC particles to form mullite, which exhibited excellent chemical stability and improved the mechanical properties and chemical stability of the supports. The porous SiC supports for zeolite membrane displayed obvious three-dimensional connected pore structure, with smooth inner surface of the pores and obvious connection neck between the particles. The porous SiC supports for zeolite membrane showed good in situ mullite bonding between the particles, and high permeability. It has a porosity of 36.3%, an average pore size of 1.42 µm and a bending strength of 32.4 MPa. All these figures indicate good comprehensive properties that are consistent with the rigorous requirements of zeolite membrane synthesis and industrial application. | A novel preparation of high permeation SiC supports for NaA zeolite membrane by in situ reaction bonding | 10.1007/s13201-022-01612-8 |
2022-03-27 | Despite the neurodegenerative disorder Alzheimer’s disease (AD) is the most common form of dementia in late adult life, there is currently no therapy available to prevent the onset or slow down the progression of AD. The progressive cognitive decline in AD correlates with a successive accumulation of cerebral amyloid-β (Aβ) due to impaired clearance mechanisms. A significant percentage is removed by low-density lipoprotein receptor-related protein 1 (LRP1)-mediated transport across the blood–brain barrier (BBB) into the periphery. Circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to members of the low-density lipoprotein receptor protein family at the cell surface and targets them for lysosomal degradation, which reduces the number of functional receptors. However, the adverse impact of PCSK9 on LRP1-mediated brain Aβ clearance remains elusive. By using an established BBB model, we identified reduced LRP1-mediated brain-to-blood Aβ clearance due to PCSK9 across different endothelial monolayer in vitro. Consequently, the repetitive application of FDA-approved monoclonal anti-PCSK9 antibodies into 5xFAD mice decreased the cerebral Aβ burden across variants and aggregation state, which was not reproducible in brain endothelial-specific LRP1 −/− 5xFAD mice. The peripheral PCSK9 inhibition reduced Aβ pathology in prefrontal cortex and hippocampus–brain areas critically involved in memory processing—and prevented disease-related impairment in hippocampus-dependent memory formation. Our data suggest that peripheral inhibition of PCSK9 by already available therapeutic antibodies may be a novel and easily applicable potential AD treatment. | PCSK9 acts as a key regulator of Aβ clearance across the blood–brain barrier | 10.1007/s00018-022-04237-x |
2022-03-26 | Background The pathoanatomic cause of chronic low back pain (cLBP) cannot be identified for up to 90% of individuals. However, dysfunctional processing of endogenous nociceptive input, measured as conditioned pain modulation (CPM), has been associated with cLBP and may involve changes in neuronal gene expression. Epigenetic-induced changes such as DNA methylation (DNAm) have been associated with cLBP. Methods In the present study, the relationship between CPM and DNAm changes in a sample of community-dwelling adults with nonspecific cLBP ( n = 48) and pain-free controls (PFC; n = 50) was examined using reduced representation bisulfite sequencing. Gene ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were applied to identify key pathways involved in efficient versus deficient CPM. Results Based on CPM efficiency, we identified 6006 and 18,305 differentially methylated CpG sites (DMCs) with q values < 0.01 among individuals with cLBP and PFCs, respectively. Most of the DMCs were hypomethylated and annotated to genes of relevance to pain, including OPRM1 , ADRB2 , CACNA2D3 , GNA12 , LPL , NAXD , and ASPHD1 . In both cLBP and PFC groups, the DMCs annotated genes enriched many GO terms relevant to pain processing, including transcription regulation by RNA polymerase II, nervous system development, generation of neurons, neuron differentiation, and neurogenesis. Both groups also enriched the pathways involved in Rap1-signaling, cancer, and dopaminergic neurogenesis. However, MAPK-Ras signaling pathways were enriched in the cLBP, not the PFC group. Conclusions This is the first study to investigate the genome-scale DNA methylation profiles of CPM phenotype in adults with cLBP and PFCs. Based on CPM efficiency, fewer DMC enrichment pathways were unique to the cLBP than the PFCs group. Our results suggest that epigenetically induced modification of neuronal development/differentiation pathways may affect CPM efficiency, suggesting novel potential therapeutic targets for central sensitization. However, CPM efficiency and the experience of nonspecific cLBP may be independent. Further mechanistic studies are required to confirm the relationship between CPM, central sensitization, and nonspecific cLBP. | Epigenome-wide DNA methylation profiling of conditioned pain modulation in individuals with non-specific chronic low back pain | 10.1186/s13148-022-01265-z |
2022-03-24 | Background Progress towards malaria elimination has stagnated, partly because infections persisting at low parasite densities comprise a large reservoir contributing to ongoing malaria transmission and are difficult to detect. This study compared the performance of an ultrasensitive rapid diagnostic test (uRDT) designed to detect low density infections to a conventional RDT (cRDT), expert microscopy using Giemsa-stained thick blood smears (TBS), and quantitative polymerase chain reaction (qPCR) during a controlled human malaria infection (CHMI) study conducted in malaria exposed adults (NCT03590340). Methods Blood samples were collected from healthy Equatoguineans aged 18–35 years beginning on day 8 after CHMI with 3.2 × 10 3 cryopreserved, infectious Plasmodium falciparum sporozoites (PfSPZ Challenge, strain NF54) administered by direct venous inoculation. qPCR (18s ribosomal DNA), uRDT (Alere™ Malaria Ag P.f.), cRDT [Carestart Malaria Pf/PAN (PfHRP2/pLDH)], and TBS were performed daily until the volunteer became TBS positive and treatment was administered. qPCR was the reference for the presence of Plasmodium falciparum parasites. Results 279 samples were collected from 24 participants; 123 were positive by qPCR. TBS detected 24/123 (19.5% sensitivity [95% CI 13.1–27.8%]), uRDT 21/123 (17.1% sensitivity [95% CI 11.1–25.1%]), cRDT 10/123 (8.1% sensitivity [95% CI 4.2–14.8%]); all were 100% specific and did not detect any positive samples not detected by qPCR. TBS and uRDT were more sensitive than cRDT (TBS vs. cRDT p = 0.015; uRDT vs. cRDT p = 0.053), detecting parasitaemias as low as 3.7 parasites/µL (p/µL) (TBS and uRDT) compared to 5.6 p/µL (cRDT) based on TBS density measurements. TBS, uRDT and cRDT did not detect any of the 70/123 samples positive by qPCR below 5.86 p/µL, the qPCR density corresponding to 3.7 p/µL by TBS. The median prepatent periods in days (ranges) were 14.5 (10–20), 18.0 (15–28), 18.0 (15–20) and 18.0 (16–24) for qPCR, TBS, uRDT and cRDT, respectively; qPCR detected parasitaemia significantly earlier (3.5 days) than the other tests. Conclusions TBS and uRDT had similar sensitivities, both were more sensitive than cRDT, and neither matched qPCR for detecting low density parasitaemia. uRDT could be considered an alternative to TBS in selected applications, such as CHMI or field diagnosis, where qualitative, dichotomous results for malaria infection might be sufficient. | Diagnostic performance and comparison of ultrasensitive and conventional rapid diagnostic test, thick blood smear and quantitative PCR for detection of low-density Plasmodium falciparum infections during a controlled human malaria infection study in Equatorial Guinea | 10.1186/s12936-022-04103-y |
2022-03-23 | The influence of composition-dependent thermal conductivity and heterogeneous internal heating of primordial dense material on the long-term evolution of primordial reservoirs in the lower mantle of the Earth is investigated utilizing thermochemical mantle convection simulations in a 2-D spherical annulus geometry. Our results show that a reduction in the thermal conductivity of primordial dense material due to iron enrichment does not substantially alter mantle dynamics nor the long-term stability of the reservoirs of this dense material. If the primordial dense material is also enriched in heat-producing elements, the average altitude of these reservoirs slightly increases as the thermal conductivity is reduced, therefore, covering smaller core–mantle boundary areas. Our study indicates that the composition-dependent thermal conductivity of primordial material plays a second order role in the long-term evolution of Earth's mantle. Graphical Abstract | Influence of composition-dependent thermal conductivity on the long-term evolution of primordial reservoirs in Earth's lower mantle | 10.1186/s40623-022-01608-3 |
2022-03-23 | Main conclusion The proteome and its time-dependent effects reveal the importance of stress response (including expression regulation of heat-shock proteins) and fatty acid metabolism in cold adaptation and preservation of Hami melon. Abstract To better understand the molecular mechanism of how Hami melons respond to low-temperature stress, this study investigated the relevant physiological characteristics, catalytic antibody activity, and quantitative proteomics of Hami melon (Jiashi muskmelon) during low-temperature storage. Jiashi muskmelon was stored inside two refrigerators set at 21 °C (control group) and 3 °C, respectively, for 24 days. Low-temperature storage led to a significantly reduced decay rate, weight loss rate, and loss of relative conductivity. It also maintained fruit firmness, inhibited the production rate of malondialdehyde and H 2 O 2 , and induced over-expression of antioxidant enzyme and ATPase. A total of 1064 differentially expressed proteins (DEPs) were identified during low-temperature storage. Stimulation response was the main process in response to low-temperature. To further verify the proteome data, we selected four heat-shock proteins (HSP) displaying relatively high expression levels. Real-time fluorescence PCR results confirmed that HmHSP90 I , HmHSP90 II , HmHSP70 , and HmsHSP were significantly up-regulated upon low-temperature induction. These proteins may protect the Hami melon from physiological and cellular damage due to the low-temperature stress by acting alone or synergistically. Additionally, the main enrichment term of the fatty acid metabolism-related DEPs was fatty acid beta oxidation at 21 °C in contrast to fatty acid biosynthesis processes at 3 °C. It is speculated that Hami melon enhances low-temperature adaptability by slowing down the oxidative degradation of fatty acids and synthesizing new fatty acids at low temperatures. This study provides new insights into the mechanism of low-temperature adaptation and preservation in post-harvest Hami melon during cold storage. | Low-temperature adaptation and preservation revealed by changes in physiological–biochemical characteristics and proteome expression patterns in post-harvest Hami melon during cold storage | 10.1007/s00425-022-03874-7 |
2022-03-23 | Low molecular weight organic acids (LMWOAs), as active components in the rhizosphere carbon cycling, may influence the environmental behaviors of biochar colloids. This study selected the pine-wood and wheat-straw biochars (PB and WB) as two typical biochars. The effects of typical LMWOAs (oxalic acid, citric acid, and malic acid) on aggregation kinetics of PB and WB colloids were investigated under pH 4 and 6 conditions. Critical coagulation concentrations (CCCs) of both PB and WB colloids were decreased with the LMWOAs regardless of the types of biochar and the solution pH, and the most significant effect occurred in pH 4 due to more LMWOAs sorption on the biochar colloids. The different types of LMWOAs caused various CCCs changes. For example, the CCC values of PB colloids decreased from 75 mM to 56, 52, and 47 mM in the pH 4 NaCl solutions when 1 mM oxalic acid, citric acid, and malic acid were present in the suspensions, respectively. The chemical structure (functional groups) and molecular weight of LMWOAs, solution pH, and the electrophoretic mobility (EPM) of biochar co-influence the interactions between biochar colloids and LMWOAs, thus affecting the stability of biochar colloids in the presence of LMWOAs. The presence of LMWOAs accelerated the aggregation of colloidal biochar by increasing the interaction of surface bridging bonds (hydrogen bonding) and decreasing the repulsive force between colloidal biochar particles. This study showed that LMWOAs could accelerate the aggregation of biochar colloids in acidic or neutral environments and reduce the mobility of biochar colloids in soil rhizosphere. The critical coagulation concentrations (CCCs) of biochar colloids were decreased after low molecular weight organic acids (LMWOAs) incorporation. The largest reduction of CCCs in biochar colloids occurred in strong acidic conditions (pH 4). The different types of LMWOAs caused various changes of CCCs, and the malic acid reduced the most CCCs of biochar colloids. | Effects of low molecular weight organic acids on aggregation behavior of biochar colloids at acid and neutral conditions | 10.1007/s42773-022-00142-5 |
2022-03-23 | Background Overactive bladder (OAB) affects 12 to 30% of the world’s population. The accompanying urinary urgency, frequency and incontinence can have a profound effect on quality of life, leading to depression, social isolation, avoidance of sexual activity and loss of productivity. Conservative measures such as lifestyle modification and pelvic floor physical therapy are the first line of treatment for overactive bladder. Patients who fail these may go on to take medications, undergo neuromodulation or receive injection of botulinum toxin into the bladder wall. While effective, medications have side effects and suffer from poor adherence. Neuromodulation and botulinum toxin injection are also effective but are invasive and not acceptable to some patients. Methods We have developed a novel transcutaneous spinal cord neuromodulator (SCONE™ , ) that delivers multifrequency electrical stimulation to the spinal cord without the need for insertion or implantation of stimulating electrodes. Previously, multifrequency transcutaneous stimulation has been demonstrated to penetrate to the spinal cord and lead to motor activation of detrusor and external urethral sphincter muscles. Here, we report on eight patients with idiopathic overactive bladder, who underwent 12 weeks of SCONE™ therapy. Results All patients reported statistically significant clinical improvement in multiple symptoms of overactive bladder, such as urinary urgency, frequency and urge incontinence. In addition, patients reported significant symptomatic improvements as captured by validated clinical surveys. Conclusion SCONE™ therapy represents the first of its kind therapy to treat symptoms of urgency, frequency and urge urinary incontinence in patients with OAB. Trial registration The study was listed on clinicaltrials.gov ( NCT03753750 ). | Noninvasive spinal neuromodulation mitigates symptoms of idiopathic overactive bladder | 10.1186/s42234-022-00087-x |
2022-03-21 | Stretchable MXene organohydrogel contains MXene network for electron conduction and water/glycerin binary solvent for ion transmission was prepared. The MXene organohydrogel exhibits exceptionally enhanced EMI shielding performance compared to hydrogel, as well as low-temperature tolerance, anti-drying ability. Conductive hydrogels have potential applications in shielding electromagnetic (EM) radiation interference in deformable and wearable electronic devices, but usually suffer from poor environmental stability and stretching-induced shielding performance degradation. Although organohydrogels can improve the environmental stability of materials, their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ability. Here, a MXene organohydrogel is prepared which is composed of MXene network for electron conduction, binary solvent channels for ion conduction, and abundant solvent-polymer-MXene interfaces for EM wave scattering. This organohydrogel possesses excellent anti-drying ability, low-temperature tolerance, stretchability, shape adaptability, adhesion and rapid self-healing ability. Two effective strategies have been proposed to solve the problems of current organohydrogel shielding materials. By reasonably controlling the MXene content and the glycerol-water ratio in the gel, MXene organohydrogel can exhibit exceptionally enhanced EM interference shielding performances compared to MXene hydrogel due to the increased physical cross-linking density of the gel. Moreover, MXene organohydrogel shows attractive stretching-enhanced interference effectiveness, caused by the connection and parallel arrangement of MXene nanosheets. This well-designed MXene organohydrogel has potential applications in shielding EM interference in deformable and wearable electronic devices. | Environmentally Tough and Stretchable MXene Organohydrogel with Exceptionally Enhanced Electromagnetic Interference Shielding Performances | 10.1007/s40820-022-00819-3 |
2022-03-21 | Background Low birth weight (LBW) is a major factor of neonate mortality that particularly affects developing countries. However, the scarcity of data to support decision making to reduce LBW occurrence is a major obstacle in sub-Saharan Africa. The aim of this research was to determine the prevalence and associated factors of LBW at the Yako health district in a rural area of Burkina Faso. Methods A cross sectional survey was conducted at four peripheral health centers among mothers and their newly delivered babies. The mothers’ socio-demographic and obstetrical characteristics were collected by face-to-face interview or by review of antenatal care books. Maternal malaria was tested by standard microscopy and neonates’ birth weights were documented. Multivariate logistic regression was used to determine factors associated with LBW. A p -value < 0.05 was considered statistically significant. Results Of 600 neonates examined, the prevalence of low birth weight was 11.0%. Adjustment for socio-demographic characteristic, medical conditions, obstetrical history, malaria prevention measures by multivariate logistic regression found that being a primigravid mother (aOR = 1.8, [95% CI: 1.1–3.0]), the presence of malaria infection (aOR = 1.9, [95% CI: 1.1–3.5]), the uptake of less than three doses of sulfadoxine-pyrimethamine for the intermittent preventive treatment of malaria in pregnancy (IPTp-SP) (aOR = 2.2, [95% CI: 1.3–3.9]), the presence of maternal fever at the time of delivery (aOR = 2.8, [95% CI: 1.5–5.3]) and being a female neonate (aOR = 1.9, [95% CI: 1.1–3.3]) were independently associated with an increased risk of LBW occurrence. The number of antenatal visits performed by the mother during her pregnancy did not provide any direct protection for low birth weight. Conclusion The prevalence of LBW remained high in the study area. Maternal malaria, fever and low uptake of sulfadoxine-pyrimethamine doses were significantly associated with LBW and should be adequately addressed by public health interventions. | Low birth weight and its associated risk factors in a rural health district of Burkina Faso: a cross sectional study | 10.1186/s12884-022-04554-w |
2022-03-21 | Background There are several genes associated with ovarian cancer risk. Molecular changes in borderline ovarian tumor (BOT) indicate linkage of this disease to type I ovarian tumors (low-grade ovarian carcinomas). This study determined the prevalence and association of mutations in BRCA1, BRCA2, PALB2, RAD51C , and CHEK2 with the risk of BOTs. Methods The study group consisted of 102 patients with histologically confirmed BOT and 1743 healthy controls. In addition, 167 cases with ovarian cancer G1 were analyzed. The analyses included genotyping of 21 founder and recurrent mutations localized in 5 genes ( BRCA1, BRCA2, PALB2, RAD51C, and CHEK2). The risk for developing BOT and low-grade ovarian cancer, as well as the association of tested mutations with survival, was estimated. Results The CHEK2 missense mutation (c.470T>C) was associated with 2-times increased risk of BOT (OR=2.05, p =0.03), at an earlier age at diagnosis and about 10% worse rate of a 10-year survival. Mutations in BRCA1 and PALB2 were associated with a high risk of ovarian cancer G1 (OR=8.53, p =0.005 and OR=7.03, p =0.03, respectively) and were related to worse all-cause survival for BRCA1 carriers (HR=4.73, 95%CI 1.45–15.43, p =0.01). Conclusions Results suggest that CHEK2 (c.470T>C) may possibly play a role in the pathogenesis of BOT, but due to the low number of BOT patients, obtained results should be considered as preliminary. Larger more in-depth studies are required. | Association of recurrent mutations in BRCA1, BRCA2, RAD51C, PALB2, and CHEK2 with the risk of borderline ovarian tumor | 10.1186/s13053-022-00218-0 |
2022-03-20 | Background Lower respiratory tract infections are the leading cause of death in children globally and are transmitted by inhaling airborne droplets. The study demonstrated the prevalence of lower respiratory tract infections in children admitted to the Women and Children Hospital Bannu from February through November 2019. The cross-sectional study was conducted by obtaining indoor data from the official record maintained in the children’s wards. Results Males accounted for 649 (61.6%) and females 405 (38.4%) cases out of 1054 cases of the disease. Age group of ≤ 6 months showed 36.2% prevalence, followed by > 6 m ≤ 1 y (25.6%), > 1 y ≤ 2 y (17.1%), > 2 y ≤ 5 y (14.3%), > 5 ≤ 10 y (6.0%), and > 10 y ≤ 15 y (0.8%). Pediatric patients of age ≤ 2 y and ≤ 5 y contributed 78.9% and 93.3% to overall disease, respectively. The disease was at its peak in February (17.9%) while lowest in May (5.5%). The age group (≤ 6 m) was the dominant group in all months except August when replaced by the age group (> 6 m ≤ 1 y). The disease revealed higher prevalence during February-April and October-November. Conclusions Different age groups showed variation in the prevalence of the disease with an age group of ≤ 5 y contributing the largest share and seasonal peaks in the disease occurred. The present findings help in adopting strategies for effective control of the disease in different age groups of the children for their peak season. | Epidemiological studies on lower respiratory tract infection in children in the District Bannu, Khyber Pakhtunkhwa, Pakistan | 10.1186/s43168-022-00119-9 |
2022-03-19 | Engineered cementitious composites (ECC) characterizes with high strain capacity, accompanied by two notable disadvantages, i.e., low elastic modulus and severe shrinkage yet. A new type of ECC featuring relatively high tensile strain capacity, high elastic modulus as well as low shrinkage was developed by using polyethylene fiber (PE) alone (P-ECC), or hybrid combining PE fiber with steel fiber (H-ECC) in this research. The effects of sand-to-binder ratio ( s/b ) from 0.42 to 1.02 and fiber hybridization on compressive properties, tensile properties and shrinkage characteristics of ECC were systematically investigated. Experimental results indicated that the increase of s/b ratio could benefit the compressive strength, the elastic modulus and the shrinkage performance of ECC. The elastic modulus as well as the shrinkage properties of P/H-ECC were superior than those of traditional ECC. It is noted that H-ECC with extremely high s/b ratios (i.e., 0.72–1.02) exhibiting relatively high tensile strain capacity, comparable elastic modulus with normal strength concrete and obviously lower total shrinkage than traditional ECC, is an ideal and competitive material which can be utilized in critical structural elements characterized by deformation compatibility and desirable ductility. | High-modulus and low-shrinkage hybrid-fiber reinforced engineered cementitious composites (ECC) | 10.1617/s11527-022-01930-y |
2022-03-18 | Background Potato ( Solanum tuberosum L.) is one of the world's most important crops, the cultivated potato is frost-sensitive, and low-temperature severely influences potato production. However, the mechanism by which potato responds to low-temperature stress is unclear. In this research, we apply a combination of second-generation sequencing and third-generation sequencing technologies to sequence full-length transcriptomes in low-temperature-sensitive cultivars to identify the important genes and main pathways related to low-temperature resistance. Results In this study, we obtained 41,016 high-quality transcripts, which included 15,189 putative new transcripts. Amongst them, we identified 11,665 open reading frames, 6085 simple sequence repeats out of the potato dataset. We used public available genomic contigs to analyze the gene features, simple sequence repeat, and alternative splicing event of 24,658 non-redundant transcript sequences, predicted the coding sequence and identified the alternative polyadenylation. We performed cluster analysis, GO, and KEGG functional analysis of 4518 genes that were differentially expressed between the different low-temperature treatments. We examined 36 transcription factor families and identified 542 transcription factors in the differentially expressed genes, and 64 transcription factors were found in the AP2 transcription factor family which was the most. We measured the malondialdehyde, soluble sugar, and proline contents and the expression genes changed associated with low temperature resistance in the low-temperature treated leaves. We also tentatively speculate that StLPIN10369.5 and StCDPK16 may play a central coordinating role in the response of potatoes to low temperature stress. Conclusions Overall, this study provided the first large-scale full-length transcriptome sequencing of potato and will facilitate structure–function genetic and comparative genomics studies of this important crop. | Full-length transcriptome sequencing reveals the molecular mechanism of potato seedlings responding to low-temperature | 10.1186/s12870-022-03461-8 |
2022-03-18 | Abstract The present study aimed to determine the effects of low-temperature plasma (LTP) on seed germination, physiological, and genetic features of Foeniculum vulgare Mill. Fennel seeds were divided into four groups: a control group and three experimental groups. The experimental groups were exposed to LTP for 5, 10, and 20 min. Then the seeds of the experimental and control groups were grown for 21 days. Subsequently, total sugar levels, activity and expression of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) enzymes, total flavonoids, and malondialdehyde (MDA) levels in both LTP-treated seeds and the control group were examined. Results showed that the concentration of sugar in the experimental groups increased significantly in comparison with the control group. SOD activity in 5 min, CAT in 5 and 10 min, and APX in all LTP treatments increased significantly compared with the control group. In addition, the expression of genes encoding these enzymes significantly increased in all groups. LTP treatments also increased total flavonoids and significantly reduced MDA. The study concluded that priming of the fennel seeds with low-temperature plasma treatment may increase their germination and vigor and improve plants’ resistance by changing their antioxidant system. | Low Temperature Plasma Affects Physiological and Genetic Attributes of Foeniculum vulgare | 10.1134/S1021443722020029 |
2022-03-17 | Cell-free DNA (cfDNA) content in plasma has been studied as a biomarker for sepsis. Recent publications show that the cfDNA content in sepsis patients entering intensive care unit who were likely to survive had a total cfDNA concentration of 1.16 ± 0.13 μg/mL compared to 4.65 ± 0.48 μg/mL of non-survivors. Current methods for measuring cfDNA content in plasma were designed to amplify and measure low concentrations of specific DNA, making them unsuitable for low-cost measurement of total cfDNA content in plasma. Here, we have developed a point of care (POC) device that uses a thread silicone device as a medium to store a fluorescent dye which eliminates the need for preparatory steps, external aliquoting and dispensing of reagents, preconcentration, and external mixing while reducing the detection cost. The device was paired with a portable imaging system with an excitation filter at 472 ± 10 nm and an emission filter of 520 ± 10 nm that can be operated with just 100 mA current supply. The device was demonstrated for use in the quantification of buffered cfDNA samples in a range 1–6 μg/mL with a sensitivity of 5.72 AU/μg/mL and with cfDNA spiked in plasma with a range of 1–3 μg/mL and a sensitivity of 5.43 AU/μg/mL. The results showed that the device could be used as a low-cost, rapid, and portable POC device for differentiating between survivors and non-survivors of sepsis within 20 min. Graphical abstract | Single-step measurement of cell-free DNA for sepsis prognosis using a thread-based microfluidic device | 10.1007/s00604-022-05245-1 |
2022-03-15 | Abstract The aim of this study is to provide comprehensive and update information concerning the utilization of low- and medium-temperature geothermal resources in Indonesia. This study includes several utilization technologies and identifies opportunities, challenges, and issues. Furthermore, to emphasize the promising potency of these potentials by gaining a good understanding of the characteristic of low- and medium-temperature resources. A number of low- and medium-temperature fields are widely spread over 254 of the total 357 geothermal potencies. The distribution of low- and medium-temperature by location majority in Sulawesi island is about 85 of 254 locations. The distribution of these potencies by the amount of resources majority in Sumatera island, it is about 3419 MWe of total 9670 MWe calculated resources. Unfortunately, the utilization of low to medium-temperature geothermal resources has not been investigated; most of the works focus on high-temperature geothermal resources. Insufficient data and information regarding the potential of low- and medium-temperature resources lead to under-utilization. In order to boost further development of low- and medium-temperature, detailed studies should be started. There are little information and data on low- and medium-temperature, even though these potencies have a wide range application, which could be developed both direct and indirect use. Identifying the most promising area of these potencies will helps in focusing the prospects to be developed. The perspective must be changed that high-temperature prospects are no longer a high priority to be developed; there are low- and medium-temperature geothermal resources that potentially benefit. Comprehensive data and information regarding these potencies are considering as a part of the solution in geothermal development in Indonesia. In addition, understanding the characteristics of a low- and medium-temperature system will afford the information regarding its geothermal systems. Article highlights A deep review of possible applications both direct- and indirect-use is necessary to commercially exploiting the geothermal potential Utilization of low- and medium-temperature geothermal resources for various purposes of direct uses Geothermal development is greatly dependent on investor/developer attraction both of the prospects and the policy including the tariff | A comprehensive data and information on low to medium temperature geothermal resources in Indonesia: a review | 10.1007/s40948-022-00375-5 |
2022-03-15 | Background High-throughput plant phenotyping (HTPP) methods have the potential to speed up the crop breeding process through the development of cost-effective, rapid and scalable phenotyping methods amenable to automation. Crop disease resistance breeding stands to benefit from successful implementation of HTPP methods, as bypassing the bottleneck posed by traditional visual phenotyping of disease, enables the screening of larger and more diverse populations for novel sources of resistance. The aim of this study was to use HTPP data obtained through proximal phenotyping to predict yellow rust scores in a large winter wheat field trial. Results The results show that 40–42 spectral vegetation indices (SVIs) derived from spectroradiometer data are sufficient to predict yellow rust scores using Random Forest (RF) modelling. The SVIs were selected through RF-based recursive feature elimination (RFE), and the predicted scores in the resulting models had a prediction accuracy of r s = 0.50–0.61 when measuring the correlation between predicted and observed scores. Some of the most important spectral features for prediction were the Plant Senescence Reflectance Index (PSRI), Photochemical Reflectance Index (PRI), Red-Green Pigment Index (RGI), and Greenness Index (GI). Conclusions The proposed HTPP method of combining SVI data from spectral sensors in RF models, has the potential to be deployed in wheat breeding trials to score yellow rust. | Predicting yellow rust in wheat breeding trials by proximal phenotyping and machine learning | 10.1186/s13007-022-00868-0 |
2022-03-14 | As a new filler, neohexene graphitic nanoplatelets (NeHGNs), is prepared firstly by using ball milling with solid graphite and liquid neohexene. The characteristics of NeHGNs are confirmed using a variety of analytic techniques. Due to the exceptional dispersion in organic solvents ( e.g. xylene) and the good affinity with low-density polyethylene (LDPE), the NeHGN/LDPE_X (NeHGNs content (X) = 0.5, 1, or 2) nanocomposites are made easily through a solution procedure. Thus, the NeHGNs play as a competent filler for LDPE due to its outstanding properties and a chemical affinity between neohexene-functional groups and LDPE. In result, the NeHGN/LDPE_X nanocomposites show significantly improved mechanical properties ( i.e., tensile strength and Young’s modulus) and thermal stability compared to the pure LDPE. Thus, considering excellent performances and competitive price, the NeHGNs are recognized as a new prospective reinforcing filler for a variety of polyolefins. | Neohexene graphitic nanoplatelets for reinforced low-density polyethylene | 10.1007/s10965-022-02980-0 |
2022-03-14 | Background The COVID-19 pandemic revealed a substantial and unmet need for low-cost, easily accessible mechanical ventilation strategies for use in medical resource-challenged areas. Internationally, several groups developed non-conventional COVID-19 era emergency ventilator strategies as a stopgap measure when conventional ventilators were unavailable. Here, we compared our FALCON emergency ventilator in a rabbit model and compared its safety and functionality to conventional mechanical ventilation. Methods New Zealand white rabbits ( n = 5) received mechanical ventilation from both the FALCON and a conventional mechanical ventilator (Engström Carestation™) for 1 h each. Airflow and pressure, blood O 2 saturation, end tidal CO 2 , and arterial blood gas measurements were measured. Additionally, gross and histological lung samples were compared to spontaneously breathing rabbits ( n = 3) to assess signs of ventilator induced lung injury. Results All rabbits were successfully ventilated with the FALCON. At identical ventilator settings, tidal volumes, pressures, and respiratory rates were similar between both ventilators, but the inspiratory to expiratory ratio was lower using the FALCON. End tidal CO 2 was significantly higher on the FALCON, and arterial blood gas measurements demonstrated lower arterial partial pressure of O 2 at 30 min and higher arterial partial pressure of CO 2 at 30 and 60 min using the FALCON. However, when ventilated at higher respiratory rates, we observed a stepwise decrease in end tidal CO 2 . Poincaré plot analysis demonstrated small but significant increases in short-term and long-term variation of peak inspiratory pressure generation from the FALCON. Wet to dry lung weight and lung injury scoring between the mechanically ventilated and spontaneously breathing rabbits were similar. Conclusions Although conventional ventilators are always preferable outside of emergency use, the FALCON ventilator safely and effectively ventilated healthy rabbits without lung injury. Emergency ventilation using accessible and inexpensive strategies like the FALCON may be useful for communities with low access to medical resources and as a backup form of emergency ventilation. | Efficacy and safety testing of a COVID-19 era emergency ventilator in a healthy rabbit lung model | 10.1186/s42490-022-00059-x |
2022-03-12 | Background Primaquine is a pro-drug and its active metabolite is potent against mature Plasmodium falciparum gametocytes. Primaquine is metabolized by a highly polymorphic cytochrome P450 2D6 (CYP2D6) enzyme. Mutations in the gene encoding this enzyme may lead to impaired primaquine activity. This study assessed if 0.25 mg/kg single-dose primaquine is safe and sufficient to reduce transmission of gametocytes in individuals with no, reduced, or increased CYP2D6 enzyme activity. Methods Between June 2019 and January 2020 children aged 1–10 years, attending at Yombo dispensary, Bagamoyo district, with confirmed microcopy-determined uncomplicated P. falciparum malaria were enrolled in the study. The enrolled patients were treated with a standard artemether-lumefantrine regimen plus 0.25 mg/kg single-dose primaquine and followed up for 28 days for clinical and laboratory assessment. Primaquine was administered with the first dose of artemether-lumefantrine. Safety assessment involved direct questioning and recording of the nature and incidence of clinical signs and symptoms, and measurement of haemoglobin (Hb) concentration. Blood samples collected from 100 patients were used for assessment of post-treatment infectiousness on day 7 using mosquito membrane feeding assays. Molecular methods were used to determine CYP2D6 and glucose-6-phosphate dehydrogenase (G6PD) status. The primary outcome was the safety of 0.25 mg/kg single-dose primaquine based on CYP2D6 status. Results In total, 157 children [median age 6.4 (Interquartile range 4.0–8.2) years] were recruited, of whom 21.0% (33/157) and 12.7% (20/157) had reduced CYP2D6 and deficient G6PD activity, respectively. Day 3 mean absolute Hb concentration reduction was 1.50 g/dL [95% confidence interval (CI) 1.10–1.90] and 1.51 g/dL (95% CI 1.31–1.71) in reduced and normal CYP2D6 patients, respectively ( t = 0.012, p = 0.990). The day 3 mean absolute Hb concentration reduction in G6PD deficient, G6PD normal and heterozygous female was 1.82 g/dL (95% CI 1.32–2.32), 1.48 g/dL (95% CI 1.30–1.67) and 1.47 g/dL (95% CI 0.76–2.18), respectively ( F = 0.838, p = 0.435). Sixteen percent (16/98) of the patients each infected at least one mosquito on day 7, and of these, 10.0% (2/20) and 17.9% (14/78) had reduced and normal CYP2D6 enzyme activity, respectively ( x 2 = 0.736, p = 0.513). Conclusion Single-dose 0.25 mg/kg primaquine was safe and sufficient for reducing transmission of P. falciparum gametocytes regardless of CYP2D6 or G6PD status. Trial registration Study registration number: NCT03352843. | A single low dose of primaquine is safe and sufficient to reduce transmission of Plasmodium falciparum gametocytes regardless of cytochrome P450 2D6 enzyme activity in Bagamoyo district, Tanzania | 10.1186/s12936-022-04100-1 |
2022-03-11 | Accurate prediction of human pharmacokinetics using in vitro tools is an important task during drug development. Albeit, currently used in vitro systems for clearance extrapolation such as microsomes and primary human hepatocytes in suspension culture show reproducible turnover, the utility of these systems is limited by a rapid decline of activity of drug metabolizing enzymes. In this study, a multi-well array culture of primary human hepatocyte spheroids was compared to suspension and single spheroid cultures from the same donor. Multi-well spheroids remained viable and functional over the incubation time of 3 days, showing physiological excretion of albumin and α-AGP. Their metabolic activity was similar compared to suspension and single spheroid cultures. This physiological activity, the high cell concentration, and the prolonged incubation time resulted in significant turnover of all tested low clearance compounds ( n = 8). In stark contrast, only one or none of the compounds showed significant turnover when single spheroid or suspension cultures were used. Using multi-well spheroids and a regression offset approach (log(CL int ) = 1.1 × + 0.85), clearance was predicted within 3-fold for 93% (13/14) of the tested compounds. Thus, multi-well spheroids represent a novel and valuable addition to the ADME in vitro tool kit for the determination of low clearance and overall clearance prediction. Graphical Abstract | Multi-Well Array Culture of Primary Human Hepatocyte Spheroids for Clearance Extrapolation of Slowly Metabolized Compounds | 10.1208/s12248-022-00689-y |
2022-03-09 | The internet of things is a disruptive technology that has been applied as a solution to problems in many fields of monitoring environmental variables. It is supported by technologies such as wireless sensor networks, which offer many protocols and hardware platforms in the market today. Protocols such as 6LoWPAN are novel, so this work focuses on determining whether its implementation on TelosB mote is feasible; these would be placed on an experimental deployment for a particular scenario of flash floods in a sector known as “La Brigada”, in the city of Barranquilla. This proposal has not been evaluated in Colombia for this type of application, and no similar work has been done for this type of scenario. For the evaluation of 6LoWPAN, a deployment with two end nodes and a sink node has been designed, due to the monitoring section under study; 5-min tests are proposed where through round trip time traffic PINGv6 packets are generated back and forth (Echo) between a sink node and two end nodes. The results are based on the evaluation of metrics such as delay and ping packet request/response rate. The performance of these metrics is subject to test scenarios that vary according to distance, packet size, and channel scan time. Two routing options, static or dynamic, are also proposed for this application case. The tests performed yielded results in terms of better performance in the test scenarios for packets with an average size of 120 B and channel monitoring times of 1024 ms. Likewise, the use of the TelosB platform was validated as a viable and innovative option for a monitoring scenario to flash floods in short stretches of the city of Barranquilla—Colombia. This study is important because it can provide information on the use of the TelosB platform as a valid solution for similar application scenarios; furthermore, the tests performed can be replicated in similar studies to evaluate congestion, power consumption, routing, topologies, and other metrics. This study is providing a road map for the research community to follow the simulation scenario to apply the test to their own studies. This work also provides the guidelines for similar researchers to monitor the flood in their own regions and then compare their results with this study. | Performance analysis of 6LoWPAN protocol for a flood monitoring system | 10.1186/s13638-022-02098-3 |
2022-03-09 | Background In the pandemic time, many low- and middle-income countries are experiencing restricted access to COVID-19 vaccines. Access to imported vaccines or ways to produce them locally became the principal source of hope for these countries. But developing a strategy for success in obtaining and allocating vaccines was not easy task. The governments in those countries have faced the difficult decision whether to accept or reject offers of vaccine diplomacy, weighing the price and availability of COVID-19 vaccines against the concerns over their efficacy and safety. We aimed to analyze public opinion regarding the governmental strategies to obtain COVID-19 vaccines in three Central Asian countries, focusing particularly on possible ethical issues. Methods We searched for opinions expressed either in Russian or in the respective national languages. We provided data on the debate within three countries, drawn from social media postings and other sources. The opinion data was not restricted by source and time. This allowed collecting a wide range of possible opinions that could be expressed regarding COVID-19 vaccine supply and human participation in the vaccine trial. We recognized ethical issues and possible questions concerning different ethical frameworks. We also considered scientific data and other information, in the process of reasoning. Results As a result, public views on their respective government policies on COVID-19 vaccine supply ranged from strongly negative to slightly positive. We extracted the most important issues from public debates, for our analysis. The first issue involved trade-offs between quantity, speed, price, freedom, efficacy, and safety in the vaccines. The second set of issues arose in connection with the request to site a randomized trial in one of the countries (Uzbekistan). After considering additional evidence, we weighed individual and public risks against the benefits to make specific judgements concerning every issue. Conclusions We believe that our analysis would be a helpful example of solving ethical issues that can arise concerning COVID-19 vaccine supply around the world. The public view can be highly critical, helping to spot such issues. An ignoring this view can lead to major problems, which in turn, can become a serious obstacle for the vaccine coverage and epidemics’ control in the countries and regions. | Social network-based ethical analysis of COVID-19 vaccine supply policy in three Central Asian countries | 10.1186/s12910-022-00764-1 |
2022-03-07 | Main conclusion Exogenous ABA played a positive role in the accumulation and biosynthesis of aroma components of postharvest kiwifruit after low-temperature storage, especially the esters production during ripening. Abstract Low-temperature storage (LTS) generally affects the aroma formation associated with the decrease in aroma quality in kiwifruit. In this work, abscisic acid (ABA) treatment after LTS increased the production of aroma components in postharvest kiwifruit and enhanced the related enzyme activity, especially alcohol acyltransferase (AAT), branched amino acid transaminase (BCAT) and hydroperoxide lyase (HPL). Corresponding to the enzyme activity, the gene expression of AchnAAT , AchnADH , AchnBCAT and AchnHPL was significantly up-regulated by ABA. The principal component analysis further illustrated the differences in aroma components between ABA and the control. The positive correlation of aroma accumulation with the expression levels of AchnPDC and AchnLOX and the enzyme activities of BCAT and pyruvate decarboxylase (PDC) was also revealed by correlation analysis. In addition, the promoter sequences of the key genes involved in aroma biosynthesis contained multiple cis-elements (ABRE and G-box) of ABA-responsive proteins. Combining the transcriptome sequencing data, the promoting role of ABA signaling in the regulation of aroma biosynthesis of postharvest kiwifruit after LTS was discussed. This study would provide a reference for improving aroma quality of postharvest kiwifruit after LTS, as well the molecular mechanism of kiwifruit aroma fading after LTS. | Exogenous ABA promotes aroma biosynthesis of postharvest kiwifruit after low-temperature storage | 10.1007/s00425-022-03855-w |
2022-03-07 | Background Though the utilization of traditional medicine has been proposed for modern drug research and development (R&D), limited research has discussed its feasible paths. In this commentary, we summarized key factors for new drug R&D under limited resources by reviewing China’s discovery of artemisinin, and raised suggestions to utilize traditional medicines in low- and middle-income countries (LMICs). Main text We suggested that systematic utilization of traditional medicine, outstanding synergy of research units at all levels and timely information-sharing mechanism should be achieved to establish a comprehensive and efficient R&D system, especially under low-resource settings. In the case of artemisinin discovery, Chinese scientists integrated documented traditional medicine experiences and modern approaches to develop drug candidates timely. Due to limited R&D resources, China adopted a collaborative way, motivating nearly all domestic research units at different levels, to develop antimalarial products. Moreover, the excellent synergy among all units through efficient information-sharing mechanisms greatly avoided work repetition and accelerated the R&D process. Conclusion Traditional medicines inspires drug discoveries in LMICs, while a comprehensive and efficient R&D system could accelerate its R&D process and save investment. The discovery of artemisinin in China gave a reliable pattern to promote sustainable development of traditional medicines and a good example to realize R&D of traditional medicine under low-resource settings. | Drug research and development opportunities in low- and middle-income countries: accelerating traditional medicine through systematic utilization and comprehensive synergy | 10.1186/s40249-022-00954-4 |
2022-03-04 | Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disorder, characterized by the presence of eosinophilic inclusions (NIIs) within nuclei of central and peripheral nervous system cells. This study aims to identify the components of NIIs, which have been difficult to analyze directly due to their insolubility. In order to establish a method to directly identify the components of NIIs, we first analyzed the huntingtin inclusion-rich fraction obtained from the brains of Huntington disease model mice. Although the sequence with expanded polyglutamine could not be identified by liquid-chromatography mass spectrometry, amino acid analysis revealed that glutamine of the huntingtin inclusion-rich fraction increased significantly. This is compatible with the calculated amino acid content of the transgene product. Therefore, we applied this method to analyze the NIIs of diseased human brains, which may have proteins with compositionally biased regions, and identified a serine-rich protein called hornerin. Since the analyzed NII-rich fraction was also serine-rich, we suggested hornerin as a major component of the NIIs. A specific distribution of hornerin in NIID was also investigated by Matrix-assisted laser desorption/ionization imaging mass spectrometry and immunofluorescence. Finally, we confirmed a variant of hornerin by whole-exome sequencing and DNA sequencing. This study suggests that hornerin may be related to the pathological process of this NIID, and the direct analysis of NIIs, especially by amino acid analysis using the NII-rich fractions, would contribute to a deeper understanding of the disease pathogenesis. | Hornerin deposits in neuronal intranuclear inclusion disease: direct identification of proteins with compositionally biased regions in inclusions | 10.1186/s40478-022-01333-8 |
2022-03-03 | Phosphorus (P) is one of the macronutrients essential for plant growth and development. Rice ( Oryza sativa L.) is sensitive to P starvation and its deficiency influences many key plant functions, resulting in crop yield penalties. Although the hybrid rice segment is well-known for its yield heterosis, P deficiency and bacterial leaf blight diseases are evident limitations. APMS6B, the female parent of DRRH-3 is susceptible to low P and bacterial blight disease. In the present study, the improvement of APMS6B to P starvation and resistance to bacterial leaf blight (BB) was carried out using the marker-assisted backcross breeding approach. Kasalath (+ Pup1 QTL) was used as a donor, and a promising IL (ATR 594-1) at BC 1 F 4 generation was identified with 81.15% of recurrent parent genome recovery. Concurrently, this IL was intercrossed with GU-2 (+ Xa21 and Xa38 ). Intercross F 1 s (ICF 1 ) hybridity was confirmed through foreground selection having maximum RPGR (88.29%) and was selfed to produce ICF 2 . The resultant progenies were phenotyped for BB using Xoo inoculum (IX-020), simultaneously genotyped with gene-specific functional SSR markers for Xa21 and Xa38 . The identified BB-resistant plants were subjected to foreground selection for Pup1 . Four promising ICF 3 plants (BP-10-1, BP-10-3, BP-10-5, and BP-10-15 with Xa21, Xa38, and Pup1 ) along with parents and checks were screened both in low P plot (< 2 kg P 2 O 5 ha −1 ) as well as in normal plot (> 25 kg P 2 O 5 ha −1 ) during dry and wet seasons 2018. The field evaluation identified four promising intercrossed lines with better root growth in the primary root length of extracted zone and root volume. In addition, fewer reductions in grain yield (39.10%) under P starvation and less susceptibility indices values (< 1) for BB were observed. These lines may be exploited in the CMS conversion and development of climate-resilient, biotic and abiotic stress-tolerant rice hybrids. | Stacking of Pup1 QTL for low soil phosphorus tolerance and bacterial blight resistance genes in the background of APMS6B, the maintainer line of rice hybrid DRRH-3 | 10.1007/s10681-022-02987-0 |
2022-03-02 | Background Listeria monocytogenes is a foodborne pathogen that causes listeriosis in humans. This pathogen activates multiple regulatory mechanisms in response to stress, and cobalamin biosynthesis might have a potential role in bacterial protection. Low temperature is a strategy used in the food industry to control bacteria proliferation; however, L. monocytogenes can grow in cold temperatures and overcome different stress conditions. In this study we selected L. monocytogenes List2-2, a strain with high tolerance to the combination of low temperature + copper, to understand whether the cobalamin biosynthesis pathway is part of the tolerance mechanism to this stress condition. For this, we characterized the transcription level of three cobalamin biosynthesis-related genes ( cbiP , cbiB, and cysG ) and the eutV gene, a transcriptional regulator encoding gene involved in ethanolamine metabolism, in L. monocytogenes strain List2-2 growing simultaneously under two environmental stressors: low temperature (8 °C) + copper (0.5 mM of CuSO 4 × 5H 2 O). In addition, the gene cbiP , which encodes an essential cobyric acid synthase required in the cobalamin pathway, was deleted by homologous recombination to evaluate the impact of this gene in L. monocytogenes tolerance to a low temperature (8 °C) + different copper concentrations. Results By analyzing the KEGG pathway database, twenty-two genes were involved in the cobalamin biosynthesis pathway in L. monocytogenes List2-2. The expression of genes cbiP , cbiB, and cysG, and eutV increased 6 h after the exposure to low temperature + copper. The cobalamin cbiP mutant strain List2-2Δ cbiP showed less tolerance to low temperature + copper (3 mM) than the wild-type L. monocytogenes List2-2. The addition of cyanocobalamin (5 nM) to the medium reverted the phenotype observed in List2-2Δ cbiP . Conclusion These results indicate that cobalamin biosynthesis is necessary for L. monocytogenes growth under stress and that the cbiP gene may play a role in the survival and growth of L. monocytogenes List2-2 at low temperature + copper. | Cobalamin cbiP mutant shows decreased tolerance to low temperature and copper stress in Listeria monocytogenes | 10.1186/s40659-022-00376-4 |
2022-03-01 | Comparative results are provided for Charpy V-notch impact bending tests of base metal and 09G2S steel welded joint metal before and after prolonged heat treatment (1200°C, 3.7 h exposure) with plotting of ductile–brittle transition curves and analysis of fracture surfaces after testing. Welded joints of 09G2S steel sheets with each other are prepared by automatic argon-arc welding with a consumable electrode in accordance with PNAE G-7-009-89. It is shown that in the temperature range from 200°С to room temperature impact strength of weld metal in the as-supplied condition is 2–2.5 times lower, and the beginning of ductile–brittle transition temperature is 90°С higher than for base metal. Long-term heat treatment expands the range of base metal ductile–brittle transition temperatures by 30°C and shifts the range of ductile–brittle transition temperatures in weld metal by at least 20°C towards higher temperatures. | Impact Strength of Low-Carbon Steel 09G2S Welded Joint Metal | 10.1007/s11015-022-01286-2 |
2022-03-01 | Heat, entropy and temperature are the key fundamental concepts of thermodynamics. The present work gives a concise overview of the fundamentals and applications of these basic notions of physics, including the new developments on this issue. These include the finite-size systems and the negative absolute temperatures. We suggest to discuss these issues under a new angle, namely by considering such systems as certain exotic thermodynamic states. For the ordinary thermodynamic states temperature increases with increasing energy. It changes from zero, asymptotically approaching positive values (up to infinity) when the energy increases. For exotic thermodynamic states the entropy may not increase when the energy increases, i.e., when energy is added to the system. This concise review discusses and critically examines various opinions and both the applications and foundations of the negative absolute temperature concept. We are focusing on the analysis of physical clarity of the various approaches to the problem as well as on their consistency with the basic notions of statistical thermodynamics such as the thermodynamic limit. | The Exotic Thermodynamic States and Negative Absolute Temperatures | 10.1007/s10909-021-02666-9 |
2022-03-01 | In this paper, the hot deformation behavior of Fe–30Mn–10Al–1C low-density steel was investigated by Gleeble-1500D thermomechanical simulator at a temperature range of 850–1100 °C and a strain rate range of 0.01–10 s –1 . The constitutive equation and dynamic recrystallization (DRX) kinetic model of the experimental steel were established. Processing maps under different strains were drawn to explore the optimum hot working parameters of the steel. The results show that the flow stress decreases with increasing deformation temperature and increases with increasing strain rate. The average activation energy of hot deformation ( Q ) was calculated to be 391.57 kJ/mol. The volume fraction of DRX grains increases with the increase in strain with a sigmoid-shape curve. Dislocation slip is the predominant deformation mechanism of the experimental steel with increasing hot compression temperature. The optimum hot working parameters of the experimental steel are: a deformation temperature of 975–1100 °C, a strain rate in the range 0.01–1 s –1 , and the efficiency of power dissipation of 36–64%. | Hot Deformation Behavior, Dynamic Recrystallization and Processing Map of Fe–30Mn–10Al–1C Low-Density Steel | 10.1007/s12666-021-02462-9 |
2022-03-01 | The harsh environment will reduce the interlayer bonding quality of mass concrete and cause plastic cracking. These defects will seriously affect the safety and durability of the structure. This study tested the layer state (water content and penetration resistance), interlayer mechanical properties, and early-age crack resistance of concrete to evaluate the impact of extreme weather on concrete interlayer properties and crack resistance. Furthermore, the interlayer splitting tensile strength of concrete under different treatment measures (covering insulation quilts and artificial grooves) was analyzed to find a method to reduce the construction risk of mass concrete. At the same time, the early-age crack resistance of concrete under different treatment measures (covering insulation quilts and adding PVA fibers) was evaluated. The results showed that the interlayer splitting tensile strength of concrete decreased by 50%, 40%, 29%, and 70%, respectively, compared with bulk concrete under extreme weather conditions (high temperature, strong winds, steep descent in temperature, and short-time heavy rainfall). Covering insulation quilts can reduce the construction risk of concrete under extreme weather conditions such as high temperature, strong winds and steep descent in temperature. This is mainly due to the fact that insulation quilt reduces the impact of the external environment on the concrete and effectively prevents the evaporation of moisture inside the concrete. In addition, covering insulation quilts can reduce the total cracking area of concrete under extreme weather conditions (strong winds and dry-heat, strong winds and cold waves, and short-time heavy rainfall) by 85–100%. At the same time, adding PVA fibers can inhibit the generation and expansion of micro-cracks on the concrete surface. This is due to the bridging and cracking resistance of PVA fibers. | RETRACTED ARTICLE: Research on Construction Risks and Countermeasures of Concrete Dam | 10.1186/s40069-022-00501-3 |
2022-03-01 | A linear elastic fracture mechanics method is proposed to investigate the fracture behavior of hot mix asphalt and warm mix asphalt; this method was used in this study to calculated the fracture toughness of hot mix asphalt and warm mix asphalt containing 3% Sasobit at low temperatures (0, − 10, and – 20 °C) and two types of bitumen (60/70 and 85/100). A semi-circular specimen with an edged crack under three-point bending load mode was used to create different loading modes, including pure mode I and pure mode II, to test the fracture toughness. The critical stress intensity factor was calculated using the critical load obtained from the failure test. The shape factor was determined from finite element analysis. The results show that hot mix asphalt has a higher fracture toughness against crack growth than the warm mix asphalt containing Sasobit. In addition, the fracture toughness of asphalt mixture with a penetration grade of 85/100 against crack growth is more than that of the mixture with a penetration grade of 60/70. The minimum fracture toughness of hot mix asphalt and warm mix asphalt occurred in pure mode I loading condition. | Low-Temperature Fracture Toughness Study for Hot Mix Asphalt and Warm Mix Asphalt Under Pure Mode I and II Loading Condition | 10.1007/s42947-021-00024-2 |
2022-03-01 | Dense microwave dielectric ceramics of Ce 2 [Zr 1 − x (Al 1/2 Ta 1/2 ) x ] 3 (MoO 4 ) 9 (CZMAT) ( x = 0.02–0.10) were prepared by the conventional solid-state route. The effects of (Al 1/2 Ta 1/2 ) 4+ on their microstructures, sintering behaviors, and microwave dielectric properties were systematically investigated. On the basis of the X-ray diffraction (XRD) results, all the samples were matched well with Pr 2 Zr 3 (MoO 4 ) 9 structures, which belonged to the space group $$R\bar 3c$$ R 3 ¯ c . The lattice parameters were obtained using the Rietveld refinement method. The correlations between the chemical bond parameters and microwave dielectric properties were calculated and analyzed by using the Phillips—Van Vechten—Levine (P—V—L) theory. Excellent dielectric properties of Ce 2 [Zr 0.94 (Al 1/2 Ta 1/2 ) 0.06 ] 3 (MoO 4 ) 9 with a relative permittivity ( ε r ) of 10.46, quality factor ( Q × f ) of 83,796 GHz, and temperature coefficient of resonant frequency ( τ f ) of −11.50 ppm/°C were achieved at 850 °C. | Crystal structure and enhanced microwave dielectric properties of the Ce2[Zr1−x(Al1/2Ta1/2)x]3(MoO4)9 ceramics at microwave frequency | 10.1007/s40145-021-0541-7 |
2022-03-01 | Mold injection is an expensive manufacturing method; it involves several engineering-design hours and expensive alloys. Enabling the use of low-cost mold tooling can turn low-run productions economically and sustainably viable. There is a low-cost and more environmentally amicable alternative to injection molding for low-run productions based on epoxy resin molds. However, one drawback is the polymeric nature of the epoxy material, which possess low thermal conductivity, negatively affecting the injection process and thus quality of the molded pieces; as well as its low degradability rate. An opportunity arises for improving the performance of epoxy resin molds by studying the effect of embedding thermally conductive fibers in the matrix. The methodology used in this work consisted in the computational evaluation of a series of molds of composite material models built up from epoxy resin and copper fibers in different geometrical shapes and orientations. Injection simulations were carried out using the software Moldflow and the “effectiveness” of the injected parts was assessed (i.e., injection cycle time, percent volume shrinkage, and injected part deflection). Results suggest that embedding copper fibers within the epoxy matrix resin molds lowers the injection cycle time and reduces volumetric shrinkage while maintaining the deflection amplitude of the injected parts; optimum effectiveness results were obtained when copper is embedded as long fibers oriented along the principal heat flow direction. Moreover, epoxy resin can be replaced by up to a 70% volume of copper fibers, depending upon wall thickness and geometry complexity, thus lowering the impact this resin has on the environment. | Epoxy-Copper Composite Materials for Injection Mold Optimal Design: a Low-Run Production Simulative Study | 10.1007/s41660-021-00191-6 |
2022-03-01 | A feasible process for preparing lightweight building materials from the low-silicate iron tailings was developed. Various proportions of bentonite, expanded perlite and feldspar were mixed into iron tailings to serve as binder, pore former and fluxing agent, respectively. The effects of blending ratios of raw materials and firing temperatures on the final product’s properties were investigated in laboratory-scale trials. It was found that the optimal ratios of materials were 46 wt.% iron tailings, 19 wt.% bentonite, 25 wt.% expanded perlite and 10 wt.% feldspar. The best firing temperature was 900 °C. The properties of the new material were: bulk density 0.90 g cm –3 ; compressive strength 8.5 MPa; apparent porosity 42.96%; and thermal conductivity coefficient 0.222 W/(m·K), all meeting Chinese Standard Specifications for Fired Heat Preservation Brick and Block (GB 26538-2011) for MU7.5 bricks. The phase compositions and microstructure of the material specimens were analyzed by XRD and SEM, showing that the main mineral phases in the materials were quartz, hematite, mullite, anorthite, microcline and albite. The internal structure contained adequate micropores, which contributed to the mechanical properties and lightweight index of the final product. | Recycling of low-silicate iron tailings in the production of lightweight building materials | 10.1007/s10163-021-01336-y |
2022-03-01 | Plasma pyrolysis has been proposed as a viable technology for reducing volume of low level combustible radioactive wastes. Thermal analysis (TG–EGA) was done on simulated waste under flowing argon and oxygen atmospheres to determine percentage mass loss and to identify evolved gases before proceeding with plasma-based processing. Subsequently, the wastes were treated in a resistance furnace to measure mass and volume change by simulating pyrolysis conditions. XRD was used to examine the residue obtained from the laboratory experiments. Based on these findings, engineering scale plasma pyrolysis-based incineration was studied. Results and observations are discussed in the present work. | Thermal decomposition study for effective management of low level radioactive combustible solids | 10.1007/s10967-022-08210-7 |
2022-03-01 | Use of low melting temperature solder (LTS) materials in interconnect devices is a recent application as they lower the challenges of high reflow peak temperature-induced package warpage during assembly. A good candidate to overcome this challenge is a eutectic Sn-Bi system solder, with a melting temperature of 138°C and a reflow peak assembly temperature of around 185°C. However, Bi causes joint hardening and is prone to brittle fractures under mechanical bend and shock. Therefore, it is critical to understand mechanical properties of Sn-58Bi solder joints under conditions of end-use condition and applications. In this study, a series of isothermally aged 300- μ m-diameter solder balls attached to a NiAu pad surface finish, are subject to single-ball shear tests after up to 500 h aging at room temperature, 100°C and −25°C. Single-ball shear tests were performed using a multi-bond tester with 10- μ m shear height and two shear speed condition, 10 μ m/s and 100 μ m/s. The maximum shear load and the distance to the peak shear load were measured to observe the deformation behavior change. Comparative testing was also conducted for Sn-1.0Ag-0.5Cu (wt.%) aged samples for comparison. A decrease in maximum shear strength and loss of ductility with 100°C isothermal aging, opposite to an increase in ductility with room temperature isothermal aging were observed. Isothermally aged Sn-58Bi samples reveal further loss of ductility compared to SAC105 which show increase in ductility. This phenomenon is due to the increased Bi solubility into Sn at a higher temperature range. The deformation behavior for both Sn-58Bi and SAC105 were observed and discussed on partially sheared solder joints using EBSD analysis. | Isothermal Aging Effect on Sn-58Bi Solder Interconnect Mechanical Shear Stability | 10.1007/s11664-021-09379-5 |
2022-03-01 | The generation and accumulation of heat is the major direct cause of the spontaneous combustion of coal. In the initial stage of coal spontaneous combustion, the heat is mainly released by low temperature oxidation reaction of coal. To investigate the thermal characteristics and the change of key functional groups in the process of coal oxidation, Yanghuopan coal sample was used for research. First, the heat flow curves of the Yanghuopan coal sample were measured by a microcalorimeter at different heating rates of 0.2, 0.4, and 0.6 °C min −1 . Then, the infrared spectrogram of coal oxidation process was measured by Fourier transform infrared spectroscopy. The results indicated that the oxidation process of coal occurred in stages that had distinct characteristics. When the temperature increased, the heat flow curve of coal first decreased, then increased. And the heat flow curve was divided into three stages: endothermic, slow exothermic, and fast exothermic. By the study of the key functional groups and structural parameters of the characteristic temperature point, the endothermic and exothermic processes of coal oxidation at low temperature are mainly caused by the reactions of methyl, methylene, hydroxyl and carboxyl groups. The methyl and methylene first increased and then decreased. A increase was observed in the Carboxyl group with the increase in the temperature. And the hydroxyl group decreased greatly with the increase of temperature. This information can guide firefighting operations in the field and help develop firefighting materials. | Study of thermal characteristics and functional group changes of Yanghuopan Coal during spontaneous combustion | 10.1007/s10973-021-10802-6 |
2022-03-01 | Abstract The physicochemical characteristics of the carbon material produced by methane conversion in UHF discharge plasma are determined. The material is characterized by high carbon content (99.4 wt %); the calorific value is 32.7 MJ/kg; and the packing density is 25.5 kg/m 3 . According to X-ray phase analysis, the crystalline content of the sample is ~43%. Morphologically, it consists of spherical agglomerates (no larger than 20 μm) composed of numerous nanoparticles. The mean particle size is 80–120 nm; the specific surface is 51.2 m 2 /g; and the mean pore volume is 0.25 cm 3 /g. | Characteristics of the Carbon Byproduct from Methane Conversion in UHF Discharge Plasma | 10.3103/S1068364X22030036 |
2022-03-01 | In this research, one-step synthesis of redox co-precipitation method (using sodium lauryl sulfate, KMnO 4 , and metal precursor) was well applicable in universally preparing low-dimensional Me-MnOx nanosheet catalysts with different metal doping (Me=Co, Ni, or Sn). NH 3 -SCR activity was explored to the relationship with structure morphology and physio-chemical properties via the characterization techniques of SEM, XRD, XPS, H 2 -TPR, and NH 3 -TPD. It was found that Ni-MnOx has a relatively poor activity at low-down temperature but was improved as the reaction temperature rising. Co-MnOx presented a relatively stable catalytic activity of which the NOx conversion rate can be maintained 80~90% in a wide temperature window of 100–250 °C with relatively better N 2 selectivity. Compared with Co- or Ni-modified MnOx, Sn-MnOx catalyst has an excellent low-temperature catalytic activity (93% NOx conversion at 100 °C) that was maintained > 80% before 200 °C but with poor selectivity to N 2 . Due to its nanosheet-structured solid solution structure, Sn-MnOx promoted the interaction between MnOx and SnO 2 with the increased contents of adsorbed oxygen and also the numbers of surface Lewis acid sites, which integrally promoted the NH 3 -SCR reaction at low temperature and also contributed to an acceptable resistances to water and sulfur. High content of adsorbed oxygen was beneficial to improve the catalytic activity at lower temperatures, while the electron cycle interaction of different metal valence ions will play a more important role with the increase of reaction temperature. | One-step synthesis by redox co-precipitation method for low-dimensional Me-Mn bi-metal oxides (Me=Co, Ni, Sn) as SCR DeNOx catalysts | 10.1007/s11356-021-14644-5 |
2022-03-01 | The mineral deposits in the Kachchh region of Gujarat contain bauxite of all different grades, with a huge amount of low-grade bauxite. The low-grade bauxite from Kachchh is characterized in detail using different physicochemical techniques like X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WD-XRF), field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray (EDX) detector, nitrogen adsorption/desorption isotherm at 77 K, and inductive coupled plasma-mass spectrophotometer (ICP-MS). The different mineral phases present in the low-grade bauxite were identified from the X-ray diffraction studies. The different elements present in the mineral were identified and quantified using WD-XRF and EDX measurements. The quantification of rare-earth elements particularly scandium is carried out by ICP-MS analysis. The digestion method has been optimized for the complete mineral digestion and precise measurement of scandium. The low-grade Kachchh bauxite is explored for the possible extraction of alumina and scandium. The ICP-MS analysis shows the presence of approximately 80 ppm of scandium in the low-grade bauxite. The low-grade bauxite has approximately 39% alumina, which is predominantly gibbsite in nature. The alkali digestion conditions were optimized for the maximum dissolution and extraction of gibbsite. Graphical Abstract | Exploratory Study for the Utilization of Low-Grade Kachchh Bauxite and Its Prospects for Rare-Earth Elements | 10.1007/s40831-021-00478-5 |
2022-03-01 | Abstract Pd–CeO 2 catalytic composites deposited on the surface of carbon nanomaterials (CNMs) can act as model systems for probing the nature of active sites of catalytic reactions and can be also considered as promising catalysts for low-temperature oxidation reactions. In this work, nitrogen-doped carbon nanotubes (N-CNTs) are used as a support. The Pd–CeO 2 /N-CNT catalysts are prepared using different methods of synthesis and studied by a complex of physicochemical methods. The activity of the catalysts is tested in the CO oxidation reaction. The nature of solvents and/or precipitants is varied to establish the optimal method of deposition of highly dispersed palladium and CeO 2 species on the surface of N-CNTs. It is shown that using NH 3 as a precipitant results in the preparation of more active catalysts than the one synthesized using guanidine. The deposition of Ce and Pd precursors from aqueous solutions leads to the formation of highly dispersed PdO particles but does not allow stabilizing ceria particles on the N-CNT surface. The most active Pd–CeO 2 /N-CNT catalysts containing active components in a highly dispersed state are prepared by using acetone as a solvent. Co-impregnation of the support with Ce and Pd precursors is found to be more effective than the sequential impregnation with the Ce precursor followed by the palladium precursor. Thus prepared Pd–CeO 2 /N-CNT catalysts are characterized by high activity in the reaction of CO oxidation at low temperatures; the temperature of 50% CO conversion is equal to 80 °C. The obtained results show that carbon nanomaterials can be effectively used to vary the dispersion and degree of interaction between Pd/PdO and CeO 2 components determining the catalytic efficiency in the CO oxidation reaction. | APPLICATION OF N-DOPED CARBON NANOTUBES FOR THE PREPARATION OF HIGHLY DISPERSED PdO–CeO2 COMPOSITE CATALYSTS | 10.1134/S0022476622030076 |
2022-03-01 | Abstract The fatigue failure of metals at low temperatures is considered. In this case, fatigue failure is characterized by elastoplastic cyclic deformation with elevated yield point and increase in thermal conductivity of the metals. Deformation and slip of the dislocations over specific planes are localized within thin surface layers. | Physical Aspects of Low-Temperature Fatigue | 10.3103/S1068798X2203008X |
2022-03-01 | The effect of copper content in the range of 0.8–1.4% on mechanical properties and cold resistance of low-alloy precipitation-hardening steel for fittings after heat treatment is investigated. It is established that steel containing 1.4% copper provides the maximum level of strength properties after normalizing and tempering and in this case the steel has an acceptable level of impact strength and cold resistance. The microstructure of steel with 1.4% Cu is investigated by scanning and transmission electron microscopy after tempering at different temperatures. Structure formation in steel with a high copper content during heat treatment by regimes simulating fitting preparation by hot stamping with subsequent tempering, including changes occurring with a secondary structural component, carbonitride particles, and copper particle strengthening precipitates, is studied in detail. | Effect of Copper Content and Heat Treatment Schedules on Mechanical Properties, Cold Resistance, and Microstructural Constituent Morphology in Precipitation-Hardened Steel | 10.1007/s11015-022-01285-3 |
2022-03-01 | Pb(Zr 0.49 Ti 0.51 ) 0.7 (Zn 1/3 Nb 2/3 ) 0.3 O 3 (PZN–PZT) piezoceramics with Sr 2+ ion substitution were sintered as low as 900°C by the solid-state reaction route. The specimens with various Sr 2+ ion concentrations were compared according to their microstructure, phase structure, piezoelectricity, ferroelectricity, and dielectric relaxation. The substitution of the smaller Sr 2+ ions for the A-site Pb 2+ ions in the PZN–PZT system improves the electrical properties. The samples with 4 mol% Sr 2+ substitutions have optimized piezoelectric properties (piezoelectric constant d 33 = 496 pC/N, Curie temperature T c = 244°C, electromechanical coupling coefficient k p = 0.58). Rietveld refinement from the XRD data reveals that the tetragonal lattice constants along with the a and c axes ( a , c ) for the PZN–PZT decrease with an increased Sr 2+ substitution content. The c decreases faster than the a , which leads to decreased tetragonality ( c / a ), thus leading to shrinkage of the oxygen octahedrons in the ABO 3 perovskite lattice. This lattice distortion facilitates mass transport, thereby increasing the bulk density and grain size of the perovskite PZN–PZT system. | Enhancement of Piezoelectric Properties in Low-Temperature Sintering PZN–PZT Ceramics by Sr2+ Substitution | 10.1007/s11664-021-09393-7 |
2022-03-01 | Plasma synthesis of ammonia is a potential and sustainable way of nitrogen fixation. In this work, a series of M/Al 2 O 3 (M =Co, Ni, Co–Ni) catalysts have been investigated to enhance the synthesis of NH 3 from N 2 and H 2 in a dielectric barrier discharge (DBD) plasma reactor. Under the conditions of a volume ratio of N 2 :H 2 of 1:1, a total gas flow rate of 200 mL min −1 , and a discharge temperature of 200 °C, the order of the ammonia synthesis rate filled with different catalysts was Co–Ni/Al 2 O 3 > Co/Al 2 O 3 > Ni/Al 2 O 3 > Al 2 O 3 > only plasma. And the highest ammonia synthesis rate could be obtained was 1500 μmol g −1 h −1 by using Co–Ni/Al 2 O 3 as the catalyst. Further research found that compared with single metal catalysis, on the one hand, the presence of Co–Ni bimetal reduced the total amount and strength of acidic sites on the catalyst surface, which is beneficial for the desorption of synthesized ammonia gas. On the other hand, the presence of Co–Ni bimetal enhanced the plasma discharge observed by the ICCD camera. At the same time, the electrical characterization was found changed with different catalysts added in the plasma synthesis process. Adding a Co–Ni bimetal loaded catalyst in the reaction system increased the average electric field (E) and improved the power efficiency. | Synergistic Effect of Co–Ni Bimetal on Plasma Catalytic Ammonia Synthesis | 10.1007/s11090-021-10223-1 |
2022-03-01 | The utilization of the solid powder activator for the activation of the ground granulated blast furnace slag (GGBFS) and its mixtures with low calcium fly ash (FA) was tested. Utilizing the activator in a powder form enabled to obtain ready-to-use dry mixtures, which, after the addition of mixing water, molding, and hydration, created compact solid samples. The selected procedure known as “one-part” or “just-add water” approach is beneficial with respect to the traditional two parts approach based on the utilization of the liquid alkali activators. The experiments were subdivided into two parts. The first part was focused on the selection of the solid alkali activator for GGBFS activation. In this stage, two solid powder activators: (i) sodium metasilicate (NS) and (ii) disodium silicate pentahydrate in amounts that carry 2.5, 5, and 7 wt% of Na 2 O, were tested. The second part was focused on the verification of the suitability of selected solid alkali silicate for the activation of the mixtures of GGBFS with low calcium FA (80:20 and 60:40). The evolution of the compressive strength of the prepared alkali-activated materials was studied after 2, 7, 28, and 56 days of hydration. The raw materials and hydrated samples were examined by XRFS, XRD, FTIR, and SEM techniques. The positive effect of the thermal treatment at 400 °C on the compressive strength of the prepared samples was observed. The obtained results indicate the “one-part” method as suitable for the activation of low calcium fly ash in combination with GGBFS. Graphical Abstract | Alkali Activation of Ground Granulated Blast Furnace Slag and Low Calcium Fly Ash Using “One-Part” Approach | 10.1007/s40831-022-00513-z |
2022-03-01 | A large amount of crude oils located in front of the combustion front experience low-temperature oxidation (LTO) reactions under relatively constant temperatures over a long period, as a result of the quite slow advancing speed of combustion front during an in situ combustion process. However, the isothermal LTO characteristics of crude oils are still less well understood. In this work, the evolution of mass losses and evolved gases of one crude oil and its saturates–aromatics–resins–asphaltenes (SARA) components during LTO under isothermal conditions was investigated using thermogravimetry connected with Fourier transform infrared spectroscopy. The results suggested that the mass loss at the LTO region was mostly caused by the evaporation of hydrocarbons. Almost no CO 2 was emitted from 50 to 350 °C for saturates, aromatics, and resins, whereas the absorbance of CO 2 was observed at 300 °C for asphaltenes. During LTO of the oil and its SARA components between 150 and 350 °C, the signal of compounds with C=O group was notably higher than that of compounds with C–O group. Additionally, the effect of the interactions between SARA components on the evolved gases and LTO reaction rate was analyzed. The interactions between SARA components promoted the formation of products with carbonyl group at 100 and 300 °C but inhibited the formation of these products at 200 °C. A better understanding to the gas products emitted by heavy oil LTO could be achieved based on this investigation on the SARA components. | Evolution of mass losses and evolved gases of crude oil and its SARA components during low-temperature oxidation by isothermal TG–FTIR analyses | 10.1007/s10973-021-10841-z |
2022-03-01 | Advantages in biomass pretreatment could be reached by improving lignin removal. In this study, the antioxidant butylated hydroxytoluene (BHT) was evaluated for lignin removal from biomass. In pretreatments performed at 121 °C with 50% (v/v) ethanol as solvent, the presence of BHT resulted in 45.28% and 72.45% lignin and hemicellulose removal, against its absence that resulted in 35.09% and 56.31%, respectively. The use of BHT in lignin removal under these conditions represents an improvement in the pretreatment reducing the biomass recalcitrance. FTIR analyses showed that organosolv pretreatment with BHT influenced band intensity of the pseudo-lignin, while in acid medium similarity was observed among the spectra. The enzymatic hydrolysis of pretreated biomass suffered the influence of hemicellulose and lignin removal. Pretreatments at 121 °C resulted in the highest cellulose conversion with 75% ethanol (58.67%), while pretreated biomass at 160 °C with 0.3% BHT resulted in a 59.04% of glucose yield. The use of BHT increased the lignin solubilization from the biomass in the organosolv pretreatment, increasing the effectiveness of the process, collaboration for further use of lignin. | Butylated Hydroxytoluene Improves Lignin Removal by Organosolv Pretreatment of Sugarcane Bagasse | 10.1007/s12155-021-10317-w |
2022-03-01 | Waterflooding has been practiced as a secondary recovery mechanism for many years with no regard to the composition of the injected brine. However, in the last decade, there has been an interest to understand the impact of the injected water composition and the low salinity waterflooding (LSWF) in oil recovery. LSWF has been investigated through various laboratory tests as a promising method for improving oil recovery in carbonate reservoirs. These experiments showed diverse mechanisms and results. In this study, a comprehensive review and analysis for results of more than 300 carbonate core flood experiments from published work were performed to investigate the effects of several parameters (injected water, oil, and rock properties along with the temperature) on oil recovery from carbonate rock. The analysis of the results showed that the water composition is the key parameter for successful waterflooding (WF) projects in the carbonate rocks. However, the salinity value of the injected water seems to have a negligible effect on oil recovery in both secondary and tertiary recovery stages. The study indicated that waterflooding with optimum water composition can improve oil recovery up to 30% of the original oil in place. In addition, the investigation showed that changing water salinity from LSWF to high salinity waterflooding can lead to an incremental oil recovery of up to 18% in the tertiary recovery stage. It was evident that applying the optimum composition in the secondary recovery stage is more effective than applying it in the tertiary recovery stage. Furthermore, the key parameters of the injected water and rock properties in secondary and tertiary recovery stages were studied using Fractional Factorial Design. The results revealed that the concentrations of Mg 2+ , Na + , K + , and Cl − in the injected water are the greatest influence parameters in the secondary recovery stage. However, the most dominant parameters in the tertiary recovery stage are the rock minerals and the concentration of K + , HCO 3 − , and SO 4 2− in the injected water. In addition, it appears that the anhydrite percentage in the carbonate reservoirs may be an effective parameter in the tertiary WF. Also, there are no clear relations between the incremental oil recovery and the oil properties (total acid number or total base number) in both secondary and tertiary recovery stages. In addition, the results of the analysis showed an incremental oil recovery in all ranges of the studied flooding temperatures. The findings of this study can help to establish guidelines for screening and designing optimum salinity and composition for WF projects in carbonate reservoirs. | Comprehensive investigation of low salinity waterflooding in carbonate reservoirs | 10.1007/s13202-021-01330-y |
2022-03-01 | A potential iron phosphate (FePO 4 ) catalyst was prepared using a low-temperature solid-state method for the heterogeneous Fenton-like degradation of methyl blue (MB). A variety of parameters affecting the MB removal rate, including temperature, initial pH, catalyst usage, H 2 O 2 and MB concentration, was studied in detail. The prepared FePO 4 exhibited a highly efficient catalytic reaction with seven cycle performance. In addition, a free radical masking experiment revealed the existence of a hydroxyl radical (•OH) and indicated that the degradation of MB was mainly due to the oxidation caused by •OH. This work suggests FePO 4 is an efficient material, which is responsible for the catalytic degradation of the azo dye MB through a heterogeneous Fenton-like system. | Low-Temperature Solid-State Synthesis of FePO4 as a Heterogeneous Fenton-Like Catalyst for the Degradation of Methyl Blue | 10.1007/s10812-022-01340-6 |
2022-03-01 | A technique for using an indicative library of characteristic fields in the design of low-temperature power plants with the utilization of low-grade heat of liquefied natural gas has been proposed. A classification of low-temperature power plants with low-grade heat utilization has been made according to the types of heat source and the thermodynamic cycle used. For a comparative analysis of the plants, the Carnot and Novikov efficiency criteria, thermal and exergy efficiency, specific work per kilogram of liquefied natural gas, as well as the newly proposed calculated effective efficiency have been used. The results of the analysis are presented in the form of characteristic fields, which can be used to significantly increase the accuracy of calculations and reduce the time for design and refinement of the low-temperature power plant being created (the values of efficiency and specific work are refined by 30-50% compared to the pre-design estimate according to Novikov). The proposed technique for using the library of characteristic fields in the methodological complex of calculation and design of low-temperature power plants allows significantly reducing the development time and bringing the calculated characteristics of the designed power plant as close as possible to the real ones. | Technique for Using the Indicative Library of Characteristic Fields in the Design of Low-Temperature Power Plants with Low-Grade Heat Utilization | 10.1007/s10556-022-01028-w |
2022-03-01 | The present work experimentally investigates the impacts of low-frequency ultrasound waves on the removal of low crude-oil content (500 mg/L) emulsion from a crude oil wastewater unit. A total of 32 experiments were designed using Minitab. The study did not use chemical demulsifiers in the experiments and performed the experiments using a laboratory ultrasound bath at 25 kHz and 45 kHz frequencies. The tests were designed to assess the impacts of the ultrasonic frequency, ultrasonic irradiation time, ultrasound power, and wastewater temperature on the separation efficiency. Based on the results, 25 min of irradiation time at 30 °C and in an ultrasonic bath of 45 kHz and 50 W provided the optimal operating condition. Furthermore, the study used ImageJ to measure the droplet size distribution and the average diameter before and after the ultrasound radiation for all tests. These results showed that, in optimum conditions, crude oil emulsion separation efficiency increased by 72%. | An experimental study on low-content crude oil in water emulsion using low-frequency ultrasonic waves | 10.1007/s43153-021-00215-1 |
2022-03-01 | High-grade epithermal Au–Ag veins of the Vodorazdelnaya district in far eastern Russia are hosted by Early Cretaceous volcanic rocks of the Tytylveem belt. The largest deposit is Zone 37, a 1-km long, northeast-striking vein that is up to 35-m wide, containing at least 32 t Au. The main shoot consists of crustiform—colloform banded quartz-chalcedony-adularia-sulfide veins, of low-sulfidation style. The vein is cut by late-mineral rhyolite sills and dikes. Zone 37 vein is dated at 117 ± 2 Ma, overlapping within error with the cross-cutting rhyolites (121–119 Ma) and with intrusions of the nearby Ilirney granitic pluton (119–117 Ma). The volcanic host rocks are dated at 121–115 Ma. At September Northeast, 15 km west-northwest of Zone 37, mineralisation consists of veins up to 4 m wide, with crustiform banded quartz ± chalcedony ± adularia ± chlorite, and Zn-Pb-Cu sulfides, of intermediate sulfidation style, in a 1-km-long, north-northeast striking trend. High grades are associated with gold dendrites in fine-grained quartz bands and with minor late-stage tellurides. The veins were disrupted by intrusion of rhyolite dikes and associated phreatic breccias. Some breccias host mineralisation as vein clasts and minor matrix sulfides. The Tytylveem belt is preserved below a regional unconformity that forms the base to the overlying Late Cretaceous (106–77 Ma) Okhotsk-Chukotka Volcanic Belt (OCVB). Intrusive rocks attributed to OCVB magmatism were emplaced at about 96 Ma and are associated with overprinting hydrothermal alteration, sub-economic veins and thermal resetting of some vein adularia ages at Zone 37, to 91–97 Ma. | The Dvoinoye and September Northeast high-grade epithermal Au–Ag veins, Vodorazdelnaya district, Chukotka region, Russia | 10.1007/s00126-021-01065-0 |
2022-03-01 | The clear differences between the atmosphere of Mars and the Earth coupled with the lack of a domestic research basis were significant challenges for the aerodynamic prediction and verification of Tianwen-1. In addition, the Mars entry, descent, and landing (EDL) mission led to specific requirements for the accuracy of the aerodynamic deceleration performance, stability, aerothermal heating, and various complex aerodynamic coupling problems of the entry module. This study analyzes the key and difficult aerodynamic and aerothermodynamic problems related to the Mars EDL process. Then, the study process and results of the design and optimization of the entry module configuration are presented along with the calculations and experiments used to obtain the aerodynamic and aerothermodynamic characteristics in the Martian atmosphere. In addition, the simulation and verification of the low-frequency free oscillation characteristics under a large separation flow are described, and some special aerodynamic coupling problems such as the aeroelastic buffeting response of the trim tab are discussed. Finally, the atmospheric parameters and aerodynamic characteristics obtained from the flight data of the Tianwen-1 entry module are compared with the design data. The data obtained from the aerodynamic design, analysis, and verification of the Tianwen-1 entry module all meet the engineering requirements. In particular, the flight data results for the atmospheric parameters, trim angles of attack, and trim axial forces are within the envelopes of the prediction deviation zones. | Aerodynamic design, analysis, and validation techniques for the Tianwen-1 entry module | 10.1007/s42064-021-0123-z |
2022-03-01 | Conventional anti-Stokes materials-involved deep photodynamic therapy (dPDT) requires much high-intensity irradiance due to low photosensitization efficiency. Herein, we proposed a “booster effector” approach to construct highly efficient hot band absorption phototherapeutics for low/biosafety power anti-Stokes light-triggered dPDT. Se, as “booster effector”, was introduced into hot band absorption luminophores (HBAs), which not only significantly facilitated intersystem crossing, but also simultaneously enhanced hot band excitation efficiency at v 808 , as a result successfully enabling excellent photogenerated singlet oxygen capability of HBAs under ultra-low power anti-Stokes excitation (10 mW cm −2 in vitro ). As far as we know, such low laser power-initiated photosensitization activity has never been reported in the existing anti-Stokes material systems. Importantly, FUC-SeME can self-assemble into uniform nanospheres in water, greatly boosting cellular uptake (>25-fold larger than FUC-Se ), and achieve superior cancer-killing effect (808 nm, 10 mW cm −2 , 5 min, the half-maximal inhibitory concentration IC 50 = 1.36 µM). After further PEGylation with folate-attached polymer, the resultant FUC-SeME@FA can effectively enrich at the tumor (signal-to-background ratio, 10). Under safety irradiation (330 mW cm −2 ), FUC-SeME@FA effectively inhibits deep-seated tumor progression (the tumor growth inhibition rate, 84%). This work provides a successful paradigm, possibly being more clinically beneficial than conventional anti-Stokes materials. | Se-sensitized NIR hot band absorption photosensitizer for anti-Stokes excitation deep photodynamic therapy | 10.1007/s11426-021-1179-7 |
2022-03-01 | Abstract The influence of the concentration of copper particles, compatibilizers based on low- and high-density polyethylene graft copolymers and grafted methacrylic acid chains, as well as a functionalized polymer, on the regularity of changes in the peeling resistance of copper and aluminum foil is considered. The effect of the pressing temperature of a foil-clad polymer composite on the character of adhesive destruction of the above-mentioned composites is described. It has been shown that composites with a graft copolymer of polyethylene with methacrylic acid as a polymer matrix have relatively high peeling resistance. | Adhesive Features of Functionalized Metal–Polymer Systems Based on Polyolefins | 10.1134/S1995421222010105 |
2022-03-01 | The results of calculations of a heat-utilizing refrigerating machine using waste heat from two sources at different temperatures and aggregate states are presented. The calculations were performed for a combination of six working organic fluids in different engine loading modes. The efficiency of independent and cascade heat energy extraction methods is compared. The expediency of use of a combined refrigeration cycle instead of different cycles is evaluated. | Use of Heat-Utilizing Vehicle Refrigerating Machine Using Diesel Engine Waste Heat | 10.1007/s10556-022-01037-9 |
2022-03-01 | The effect of up to 0.18% microadditions of titanium on the structure and mechanical properties of sheet low-carbon (0.07 – 0.09% C) steels with different alloying systems (C – Mn – Ti, C – Mn – V – Ti,C – Mn – Nb – Ti) is studied. The phase composition and the structure of the steels are determined. The specimens are tested for static tension and impact toughness. The content of titanium Ti cr above which fine particles of TiC carbide precipitate in the structure and elevate the strength properties at simultaneous decrease in the ductility and toughness of the steels is determined. | Microalloying of Low-Carbon Low-Alloy Steels with Titanium | 10.1007/s11041-022-00735-8 |
2022-03-01 | Sodium nitrite (NaNO 2 ) is a multifunctional meat-curing ingredient responsible for the unique reddish-pink color and flavor, microbiological safety, and shelf life extension of products. However, its use in the meat industry is controversial since NaNO 2 is an exogenous source of nitric oxide, a nitrosating (nitrosamine-forming agent) and nitrosative stress agent (peroxinitrite precursor). Therefore, there is a great consumer demand for low-nitrite or nitrite-free meat products. Although it is difficult to remove the conventional NaNO 2 owing to its beneficial properties, a partial or total substitute, without compromising the sensory attributes, may be effective. This review article presents and discusses the plant powders/extracts, atmospheric plasma, and pulsed electric field as new potential strategies for the total/partial substitution of conventional NaNO 2 in meat products. The functionality of NaNO 2 in meat products and the costs of its substitution are also provided. The information in this paper will open new vistas for scientists exploring the replacement of NaNO 2 , a hot topic for the meat industry. | New Strategies for the Total/Partial Replacement of Conventional Sodium Nitrite in Meat Products: a Review | 10.1007/s11947-021-02744-6 |
2022-03-01 | Fully utilizing the energy generated by the explosion of pulverized coal will contribute to realize the clean and efficient exploitation of coal resources. The pulverized coal explosion characteristics will be a far-reaching and important task to explore. In this paper, ten kinds of low-quality coals such as high sulfur, high ash, and low metamorphic degree coals were investigated and the minimum ignition energy (MIE), lower explosion limit (LEL), and explosion intensity (EI) parameters under different particle sizes and coal powder concentration conditions were also analyzed combined with a 1.2-L Hartmann tube and a 20-L explosion sphere experimental system. Finally, the morphological characteristics of the exploded coal powder surface were evaluated by scanning electron microscopy (SEM). The results show that the particle size is positively correlated with MIE. LEL shows an inverted “U”-shaped trend with the increasing degree of coal deterioration. The low-rank coal is more flammable and explosive. The maximum pressure P Max at the LEL concentration and maximum pressure rise rate ( dP/dt ) Max overall value is small. Here, optimum pulverized coal particle size (75μm) for explosive utilization of low-quality coal was determined. Within 50–225 g/m 3 of pulverized coal concentration range, the explosion intensity increases with increasing concentration. The smaller the particle size of pulverized coal, the greater the possibility of agglomeration of pulverized coal particles. The surface of the exploded coal particles produces more developed pores. They are irregularly shaped and have more rounded edges than the original coal. | Evaluation on explosion characteristics and parameters of pulverized coal for low-quality coal: experimental study and analysis | 10.1007/s11356-021-17170-6 |
2022-03-01 | Precipitation extremes will generally intensify in response to a warming climate. This robust fingerprint of climate change is of particular concern, resulting in heavy rainfall and devastating floods. Often this intensification is explained as a consequence of the Clausius–Clapeyron law in a warmer world, under constant relative humidity. Here, based on an ensemble of CMIP5 global climate models and high-resolution regional climate simulations, we take the example of Southwest Asia, where extreme storms will intensify beyond the Clausius- Clapeyron scaling, and propose an additional novel mechanism for this region: the unique increase in atmospheric relative humidity over the Arabian Sea and associated deep northward penetration of moisture. This increase in humidity is dictated by changes in circulation over the Indian Ocean. Our proposed mechanism is consistent with the recent, most extreme storm ever observed in the region. Our findings advance a new understanding of natural climate variability in this region, with substantial implications for climate change adaptation of the region’s critical infrastructure. | Extreme storms in Southwest Asia (Northern Arabian Peninsula) under current and future climates | 10.1007/s00382-021-05975-7 |
2022-03-01 | Sponges of the genus Aplysina Nardo, 1834 (Porifera, Demospongiae) can produce a large diversity of natural products of interest to industries such as the pharmaceutical trade. Here, we investigated the dynamics of population density, sponge size, and growth rate (GR) of three species of Aplysina over 25 months in a tropical bay on the Brazilian coast. We also analyzed how these characteristics are modulated by different environmental factors. We observed that A. solangeae was the most abundant species, followed by A. fulva and A. insularis . The dynamics of population density of A. solangeae and A. fulva could not be related to any of the environmental factors analyzed, but the population density of A. insularis was negatively related to photoperiod and rainfall. Specimens of A. solangeae were the smallest among the three species and presented a slow (negative) annual GR, and A. insularis was the species with largest size and fastest GR. Low tides were the main factor influencing the size dynamics of A. solangeae and A. fulva. The GR dynamics of A. solangeae was negatively modulated by chlorophyll-a and temperature, while the GR of the A. fulva population could be related to low tides. These important demographic data about these Aplysina spp. could be used for future management and conservation plans, especially if they are targeted for natural product discovery. | Population dynamics of three species of the genus Aplysina (Porifera, Demospongiae, Verongiida) in a tropical bay in the Western Atlantic Ocean | 10.1007/s12526-021-01257-x |
2022-03-01 | Propagation of low cycle fatigue cracks in main parts of an aviation gas turbine engine can cause sudden engine destruction during operation with catastrophic consequences. Accurate prediction of an engine low cycle fatigue durability can be accessed using finite element simulations. Main aspects of the applied approach for low cycle fatigue stable crack propagation finite element simulations in 3D specification for main parts of an aviation gas turbine engine are described in the article. These include applied formulation and procedure, descriptions of applied models and assumptions, parameters of generated grids, some results of grid convergence studies and simulation results for turbine discs. The significance of some aspects for solution accuracy such as along crack front grid resolution is demonstrated. Advancements to the applied approach are proposed which include solution under-relaxation preventing instability when large crack propagation steps are used and circular correction improving crack path prediction accuracy for bodies of revolution. The improvements result in the overall simulation accuracy increase and effort decrease up to 50%. | Enhancements for technique of stable low cycle fatigue crack propagation simulation for gas turbine engine | 10.1007/s42401-021-00106-w |
2022-03-01 | Abstract —A multi-chord beam diagnostic system for an open multiple-mirror trap GOL-NB is described. The system is based on a 10 keV ribbon beam of fast neutral hydrogen atoms generated by a wide-aperture ion injector with an arc plasma source. The plasma linear density profile is calculated from the attenuation of the beam after passing through the plasma. This paper discusses the design of the diagnostics and its capabilities, and also presents the measured profiles of the linear plasma density in the experiment on filling the trap with the starting plasma. The modernized version of diagnostics and the expected increase in its resolution are described. The prospects of using the Charge eXchange Recombination Spectroscopy (CXRS) method on the existing element base are evaluated. | Multi-Chord Beam Diagnostics of Plasma at the GOL-NB Device | 10.1134/S1063780X22030114 |
2022-03-01 | Very low frequency (VLF) (3–30 kHz) communication systems are widely used in remote and underwater scenarios due to the low propagation loss. However, the antenna size and complex impedance matching network restrict the development of portable VLF transmitters. Here, we demonstrate a compact dual-band piezoelectric artificial structure for very low frequency mechanical antenna for the enhancement of electromagnetic radiation. The mechanical antenna consisted of piezoelectric ceramic rings operating at 25.61 kHz and 35.79 kHz. A VLF communication system is designed to verify the radiation efficiency of the proposed mechanical antenna. At 25.61 kHz and 35.79 kHz, the measured magnetic field intensity can reach 0.118 nT and 0.084 nT at a distance of 5.4 m. Due to the piezoelectric artificial structure, the radiation enhancement of the proposed antenna has been experimentally demonstrated within the range of 20–40 kHz. This mechanical antenna has great potential in applications of portable, low-cost, and high-performance VLF wireless communication devices. Graphical abstract A dual-band very low frequency mechanical antenna with the piezoelectric artificial structure is proposed. The antenna consisting of varisized piezoelectric ceramic rings can work at 25.61 kHz and 35.79 kHz. With the piezoelectric artificial structure, operating frequency bands of the proposed VLF mechanical antenna are expanded. Measurements demonstrate the feasibility of the proposed mechanical antenna in VLF communication. | Dual-band piezoelectric artificial structure for very low frequency mechanical antenna | 10.1007/s42114-022-00431-4 |
2022-03-01 | For new renewable clean energy, triboelectric nanogenerators (TENGs) have shown great potential in response to the world energy crisis. Nevertheless, the alternating-current signal generated by a TENG needs to be converted into a direct-current signal to be effective in applications. Therefore, a power management circuit, comprising a clamp rectifier circuit and a mechanical switch, is proposed for the conversion and produces a signal having a low ripple coefficient. The power management circuit adopts a clamp circuit as the rectifier circuit to increase the rectified voltage, and reduces the loss resulted from the components by reducing the use of discrete components; the electronic switch in the buck regulator circuit is replaced with a mechanical switch to reduce cost and complexity. In a series of experiments, this power management circuit displayed a stable output voltage with a ripple voltage of 0.07 V, crest factor of 1.01, and ripple coefficient of 2.2%. The TENG provides a feasible method to generate stable electric energy and to supply power to low-consumption electronic devices. | Triboelectric nanogenerator with mechanical switch and clamp circuit for low ripple output | 10.1007/s12274-021-3828-7 |
2022-03-01 | Nickel-iron sulfide has shown attractive activity in electrocatalytic oxygen evolution reaction (OER). However, the effects of low valence sulfur (S 2− ) and metal species on OER in binary nickel-iron sulfide have rarely been systematically studied. Works based on post-catalysis characterization have led to the assumption that the real active species are nickel-iron oxyhydroxide, and that nickel-iron sulfide acts only as a precatalyst. Therefore, to study the role of S, Ni, and Fe for the development of nickel-iron sulfide catalyst is of self-evident importance. Herein, a facile solvothermal method is used to synthesize acetylene black coated with nickel-iron sulfide nanosheets. Electrochemical tests show that the presence of low valence S species makes the catalyst have faster OER kinetics, larger active area, and intermediate active species adsorption area. Therefore, the present study reveals the enhancing effect of low valence sulfur species (S 2− ) on OER in binary nickel-iron sulfide. In situ Raman spectroscopy shows that the generation of γ-NiOOH intermediate is essential and Fe does not directly participate in the oxygen production. Density functional theory (DFT) calculation shows that Ni-OH deprotonation is a rate-determining step for both binary nickel-iron sulfide and nickel sulfide. The addition of Fe into NiS x lightly increases the charge transfer of Ni atom to O atom, which makes deprotonation easier and thereby improves the OER performance. | Insight into sulfur and iron effect of binary nickel-iron sulfide on oxygen evolution reaction | 10.1007/s12274-021-3800-6 |
2022-03-01 | Heavy metals is a collective term describing metals and metalloids with a density higher than 5 g/cm 3 . Some of them are essential micronutrients; others do not play a positive role in living organisms. Increased anthropogenic emissions of heavy metal ions pose a serious threat to water and land ecosystems. The mechanism of heavy metal toxicity predominantly depends on (1) their high affinity to thiol groups, (2) spatial similarity to biochemical functional groups, (3) competition with essential metal cations, (4) and induction of oxidative stress. The antioxidant response is therefore crucial for providing tolerance to heavy metal-induced stress. This review aims to summarize the knowledge of heavy metal toxicity, oxidative stress and antioxidant response in eukaryotic algae. Types of ROS, their formation sites in photosynthetic cells, and the damage they cause to the cellular components are described at the beginning. Furthermore, heavy metals are characterized in more detail, including their chemical properties, roles they play in living cells, sources of contamination, biochemical mechanisms of toxicity, and stress symptoms. The following subchapters contain the description of low-molecular-weight antioxidants and ROS-detoxifying enzymes, their properties, cellular localization, and the occurrence in algae belonging to different clades, as well as the summary of the results of the experiments concerning antioxidant response in heavy metal-treated eukaryotic algae. Other mechanisms providing tolerance to metal ions are briefly outlined at the end. | Heavy metal–induced stress in eukaryotic algae—mechanisms of heavy metal toxicity and tolerance with particular emphasis on oxidative stress in exposed cells and the role of antioxidant response | 10.1007/s11356-021-18419-w |
2022-03-01 | The parameters of the plasma of a non-self-sustaining glow discharge generated inside a metal hollow cathode 300 mm long and 25 mm in inner diameter are investigated. A feature of this system is the additional injection of electrons from the auxiliary discharge plasma formed by the plasma source with a combined PINK heated and hollow cathode. The dependences and combustion modes of the non-self-sustaining glow discharge are presented and described at a pressure in the range (0.06–1.4) Pa and a combustion voltage of (70–300) V. Studies of the plasma parameters using double Langmuir probes have shown that this discharge system provides generation of the nitrogen plasma inside the hollow cathode with inhomogeneity from ±12 to ±63%. | Influence of the Discharge Burning Conditions on Distributions of the Parameters of Plasma Generated in a Non-Self-Sustaining Glow Discharge Inside a Hollow Cathode | 10.1007/s11182-022-02573-w |
2022-03-01 | Tissue engineering has played a very significant role in the medical field with an ever-growing demand for various tissue donations. One crucial factor is the fabrication of a desirable artificial three-dimensional (3D) tissue scaffold to act as the extracellular matrix (ECM), meeting the complex requirements for specific cell cultures. Existing scaffold fabrication techniques and systems used in constructing extracellular matrix are two-dimensionally limiting, expensive, and time-consuming. For instance, some simple fabrication methods cannot control fabricated structures with morphologies accurately, while others may introduce harmful organic solvents into scaffolds during the fabrication processes. To achieve an optimal scaffold for tissue engineering, we developed a novel 3D printing system capable of printing tissue scaffold structures with improved efficiency. The uniqueness of our system is the transparent diffractive optical elements (DOEs) of linear binary Fresnel lens fabricated to control the luminous intensity distribution. These DOEs of different patterns are arranged in series on a coverslip with each optical element designed to diffact and focus incident light at a particular plane within the device. Coupled with other optical components of the system, 3D woodpile scaffolds were printed in an effective and efficient one-step light exposure process to photo cross-link the polymer solution upon demand. The combination of photo cross-linking and diffractive optical technique incorporated within our system enables the patterning of polymer solutions within seconds, making large-scale fast production not only feasible, but also making printing of complex features simple. With this system, 3D two-layered woodpile structures were successfully fabricated within 3 seconds. While cell toxicity studies showed that the scaffold can be used for tissue engineering. | Printing of Woodpile Scaffold Using Fresnel Lens for Tissue Engineering | 10.1007/s40684-021-00322-x |
2022-03-01 | The aim of this scoping review was to assess the extent of the literature on the use of LED therapy to treat synovial joint disorders. The JBI methodology for scoping reviews was followed. The databases used were PUBMED, EMBASE, Scopus, Web of Science, LILACS, PEDro, Cochrane Database, Google Scholar and ProQuest. To be included, studies should have used LED as therapy, and include at least one measure related to the structures of any synovial joint. The search strategy included all keywords and indexed terms identified in the articles. Studies in any language and in any year, whether published or not, were included. The analysis of the studies was carried out by two independent reviewers. Data were extracted from articles using a data extraction tool developed by the reviewers. After carrying out the definitive search and selection, 47 publications were included: 15 clinical trials, 8 clinical protocols, 12 animal studies, 4 in vitro studies and 8 reviews on the topic. Studies have shown great variability from the device and number of diodes used, to the parameters and dosimetry chosen. Some positive effects were observed: on cell proliferation (in vitro); on anti-inflammatory biomarkers (murine models) and on pain scale (clinical trials — TMD). Although, the cause of non-significant results in clinical trials was rarely discussed: depth of penetration, dosimetry, follow-up time? Thus, future studies should focus on answering more elementary aspects about the LED effect when used alone in different synovial joints. | The use of LED therapy to treat synovial joints disorders: scoping review | 10.1007/s10103-021-03372-4 |
2022-03-01 | Seed germination plays cardinal roles in seedling establishment and their successive growth. However, seed germination is retarded by far-red (FR) enrichment under low light stress, and the inhibitory signalling mechanism remains ambiguous. Our results indicated that low light treatment, both in the open and growth chamber conditions, inhibits rice seed germination by decreasing the gibberellin (GA) contents. To explore the mechanism of GA-deficiency under low light stress, differential expression profiling of GA-anabolic, -catabolic, ABA -anabolic, -catabolic, and SLR1 was investigated, revealing that expression of ABA- anabolic, GA-catabolic genes and SLR1 was upregulated with a simultaneous downregulation of ABA-catabolic and GA-anabolic genes under low light treatment. These results suggested that FR-induced GA inadequacy is resulted by upregulation of SLR1 and GA-catabolism genes consequently increase DELLA that further subsided GA-responses in the germinating rice seeds. Moreover, we provided evidence that FR-induced GA inadequacy demotes rice seed germination by decreasing amylase activity, eventually decreasing the carbohydrate solubilization in the germinating seeds. Finally, we suggest that under low light stress, due to a retarded conversion of phytochrome A to their bioactive form, the ABA-catabolic genes were eventually upregulated with a simultaneous downregulation of GA-anabolic genes. Consequently, a lower GA pool fails to leverage the GA-dependent DELLA degradation, further shutting down the expected GA responses that reduce germination efficiency under FR-enriched light. | The role of phytochrome-mediated gibberellic acid signaling in the modulation of seed germination under low light stress in rice (O. sativa L.) | 10.1007/s12298-022-01167-7 |
2022-03-01 | Abstract Based on the linear electron accelerator LUE-75 of the A.I. Alikhanyan National Scientific Laboratory a technique for obtaining controlled primary electron beams with an intensity of 10–20 electrons per second in the energy range 15–75 MeV for elementary particle detectors calibration was developed and used. Joint work with the V.P. Dzhelepov Laboratory of Nuclear Problems (JINR, Dubna, RF) showed the efficiency of the technique. | Test Electron Beams Based on the Linear Accelerator Complex LUE-75 of A.I. Alikhanyan National Scientific Laboratory | 10.3103/S1068337222010042 |
2022-03-01 | Because of global environmental problems, low-carbon agriculture has gained increasing importance both in developed and developing countries. Hence, there is a need to find ways to develop more efficient agricultural systems. The purpose of this article is to identify the drivers of low-carbon agriculture on farms in the Wielkopolska region (in Poland). We aimed to take an original approach to investigate low-carbon agriculture with a unique set of different economic and environmental variables and contribute to the literature, which is not very extensive in terms of microeconomic research, including research on farmers in the Wielkopolska region. Therefore, we employed a multiple-factor measurement model for structural equation modeling (SEM) of data collected individually from 120 farms in 2020. As a result, we formulated the following conclusions: the increasing productivity of factors (land, labor, and capital) have a positive effect on low-carbon farming, just as increasing fertilizer and energy efficiency. Moreover, thermal insulation is also important for low-carbon agriculture, with efficiency of fertilizer use being the most important factor. We believe that the issues of farm use of fertilizers and thermal insulation of buildings should be more broadly included in energy policy, both at the national and the European Union (EU) levels. Some of these factors however are already present in the common agricultural policy (CAP) for 2021–2027. | What drives low-carbon agriculture? The experience of farms from the Wielkopolska region in Poland | 10.1007/s11356-021-17022-3 |
2022-03-01 | Iron toxicity is a major challenge faced by plants in hypoxic soils; however, the consequences of such combined stress for soybean ( Glycine max ) remain to be determined. Here we assessed the physiological responses of soybean plants exposed to hypoxia and a high concentration of iron. Soil-grown plants cultivated in a greenhouse until the vegetative stage were transferred to a hydroponic system containing nutrient solution and subjected to two oxygen conditions (normoxia (6.2 mg L -1 ) and hypoxia (0.33 mg L -1 )) and two iron concentrations (Fe-EDTA) (0.09 and 1.8 mM) for 72 h. During hypoxia, high concentrations of iron in the nutrient solution resulted in increased iron accumulation in roots and leaves. Under this condition, the concentrations of zinc, nitrogen, potassium, and calcium decreased in the roots, while the concentration of nitrogen and magnesium decreased in the leaves. Additionally, during hypoxia, the higher concentration of iron led to an increase in the activity of the antioxidant enzymes in roots and leaves, while decreased the levels of the photosynthetic pigments, leaf gas exchange, and plant growth. In conclusion, high iron concentration in the root medium results in a considerably more severe damage condition to soybean plants under hypoxia compared to plants grown under low iron availability. | Iron toxicity increases oxidative stress and impairs mineral accumulation and leaf gas exchange in soybean plants during hypoxia | 10.1007/s11356-021-17397-3 |
2022-03-01 | There is increasing evidence that patient heterogeneity significantly hinders advancement in clinical trials and individualized care. This study aimed to identify distinct phenotypes in extremely low birth weight infants. We performed an agglomerative hierarchical clustering on principal components. Cluster validation was performed by cluster stability assessment with bootstrapping method. A total of 215 newborns (median gestational age 27 (26–29) weeks) were included in the final analysis. Six clusters with different clinical and laboratory characteristics were identified: the “Mature” (Cluster 1; n = 60, 27.9%), the mechanically ventilated with “adequate ventilation” (Cluster 2; n = 40, 18.6%), the mechanically ventilated with “poor ventilation” (Cluster 3; n = 39, 18.1%), the “extremely immature” (Cluster 4; n = 39, 18.1%%), the neonates requiring “Intensive Resuscitation” in the delivery room (Cluster 5; n = 20, 9.3%), and the “Early septic” group (Cluster 6; n = 17, 7.9%). In-hospital mortality rates were 11.7%, 25%, 56.4%, 61.5%, 45%, and 52.9%, while severe intraventricular hemorrhage rates were 1.7%, 5.3%, 29.7%, 47.2%, 44.4%, and 28.6% in clusters 1, 2, 3, 4, 5, and 6, respectively ( p < 0.001). Conclusion : Our cluster analysis in extremely preterm infants was able to characterize six distinct phenotypes. Future research should explore how better phenotypic characterization of neonates might improve care and prognosis. What is Known: • Patient heterogeneity is becoming more acknowledged as a cause of clinical trial failure. • Machine learning algorithms can find patterns within a heterogeneous group. What is New: • We identified six different phenotypes of extremely preterm infants who exhibited distinct clinical and laboratorial characteristics. | Identifying clinical phenotypes in extremely low birth weight infants—an unsupervised machine learning approach | 10.1007/s00431-021-04298-3 |
2022-03-01 | Exploring the low-carbon energy transformation pathway is vital to coordinate economic growth and environmental improvement for achieving China’s carbon peak target. Three energy-target scenarios are developed in this paper, considering the targets of energy structure, electrification rate, and carbon mitigation towards 2030 announced by the Chinese government. A dynamic multi-sectoral computable general equilibrium model, CHINAGEM, is employed to examine the economic and environmental effects under different pathways of long-term low-carbon transformation. It detects that China’s energy structure would substantially transfer to the low-carbon and clean one, whereas CO 2 , SO 2 , and NO X emissions in 2020–2030 would vastly abate along with all three energy-target scenarios. Different pathways would produce varying positive impacts on China’s macro-economy and achieve the different extent of double dividend effects. It is highly conceivable for China to peak its carbon emission at 12.4 GtCO 2 by 2028 if it serves the comparatively more stringent low-carbon transformation pathways. | Could China’s long-term low-carbon energy transformation achieve the double dividend effect for the economy and environment? | 10.1007/s11356-021-17202-1 |
2022-03-01 | Osteoarthritis (OA) and rheumatoid arthritis (RA) are common inflammation-associated cartilage degenerative diseases. Recent studies have shown that low-level diode laser treatment can reduce inflammatory cytokine expressions in cartilage. We recently reported that high-frequency low-level diode laser irradiation attenuates matrix metalloproteinases (MMPs) expression in human primary chondrocytes. However, the molecular mechanism underlying the effect of high-frequency low-level diode laser on chondrocytes remains unclear. Therefore, we aimed to elucidate the effect of high-frequency low-level diode laser irradiation on inflammatory cytokine expression in human primary chondrocytes. Normal human articular chondrocytes were treated with recombinant interleukin-1 beta (IL-1β) for 30 min or 24 h and irradiated with a high-frequency NIR diode laser at 8 J/cm 2 . The expression of IL-1β, interleukin-6, and tumor necrosis factor-alpha was assessed using western blot analysis. To evaluate the nuclear factor-kappa B (NF-κB) signaling pathway, the phosphorylation, translocation, and DNA-binding activity of NF-κB were detected using western blot analysis, immunofluorescence analysis, electrophoretic mobility shift assay, and enzyme-linked immunosorbent assay analysis. High-frequency low-level diode laser irradiation decreased inflammatory cytokine expression in IL-1β-treated chondrocytes. Moreover, high-frequency low-level diode laser irradiation decreased the phosphorylation, nuclear translocation, and DNA-binding activity of NF-κB in the IL-1β-treated state. However, irradiation alone did not affect NF-κB activity. Thus, high-frequency low-level diode laser irradiation at 8 J/cm 2 can reduce inflammatory cytokine expressions in normal human articular chondrocytes through NF-κB regulation. These findings indicate that high-frequency low-level diode laser irradiation may reduce the expression of inflammatory cytokines in OA and RA. | High-frequency near-infrared diode laser irradiation suppresses IL-1β-induced inflammatory cytokine expression and NF-κB signaling pathways in human primary chondrocytes | 10.1007/s10103-021-03371-5 |
2022-03-01 | Few studies have assessed mining-associated water pollution using spectral characteristics. We used high-resolution multispectral data acquired by unmanned aerial drones combined with in situ chemical data to assess water quality parameters in 12 relatively small water bodies located in the Tharsis complex, an abandoned mining area in the Iberian pyrite belt (SW Spain). The spectral bands of Micasense RedEdge-MX Dual and spectral band combinations were used jointly with physicochemical data to estimate water quality parameters and develop reliable empirical models using regression analysis. Physicochemical parameters including pH, ORP, EC, Al, Cu, Fe, Mn, S, Si, and Zn were estimated with high accuracy levels (0.81 < R 2 < 0.99, 4 < RMSE% < 75, 0.01 < MAPE < 0.97). In contrast, the observed and modelled values for Ba, Ca, and Mg did not agree well (0.42 < R 2 < 0.70). The best-fitted models were used to generate spatial distribution maps, providing information on water quality patterns. This study demonstrated that using empirical models to generate spatial distribution maps can be an effective and easy way to monitor acid mine drainage. Eine Bewertung bergbaubedingter Wasserverschmutzungen durch Spektralbanduntersuchungen erfolgte bislang nur selten. In dieser Untersuchung werden hochauflösende multispektrale Daten, die von unbemannten Drohnen erfasst worden sind, mit chemischen in-situ-Daten kombiniert, um Wasserqualitätsparameter in 12 relativ kleinen Gewässern im Tharsis-Komplex, einem stillgelegten Bergbaugebiet im iberischen Pyritgürtel (Südwestspanien), zu bewerten. Die Spektralbänder des Micasense RedEdge-MX Dual sowie Spektralbandkombinationen sind zusammen mit physikalisch-chemischen Daten verwendet worden, um Wasserqualitätsparameter abzuschätzen und zuverlässige empirische Modelle mit Hilfe der Regressionsanalyse zu entwickeln. Physikalisch-chemische Parameter wie pH-Werte, Redoxpotentiale, Elektr. Leitfähigkeiten, Al-, Cu-, Fe-, Mn-, S-, Si- und Zn-Gehalte wurden mit hoher Genauigkeit abgeschätzt (0.81<R²<0.99, 4<RMSE%<75, 0.01<MAPE<0.97). Im Gegensatz dazu stimmten die beobachteten und modellierten Werte für die Ba-, Ca- und Mg-Gehalte nicht gut überein (0.42<R²<0.70). Die am Besten angepassten Modelle wurden verwendet, um räumliche Verteilungskarten zu erstellen, welche Rückschlüsse über Wasserqualitätsmuster zulassen. Diese Untersuchung hat gezeigt, dass die Verwendung empirischer Modelle zur Erstellung räumlicher Verteilungskarten eine wirksame und einfache Methode zur Überwachung der sauren Bergbauabwässern sein kann. 很少有研究利用光谱特征评价采矿相关的水污染。采用无人机高分辨率多光谱数据与现场化学数据相结合方法, 评估了伊比利亚黄铁矿带 (西班牙西南部) Tharsis 废弃矿区的12个小型水体的水质参数。研究将无人机的Micasense RedEdge-MX Dual光谱带和光谱带组合数据与物理化学数据联合使用, 估算出水质参数, 建立了可靠的回归经验模型。物理化学参数pH, ORP, EC, Al, Cu, Fe, Mn, S, Si和Zn的估算精度较高 (0.81<R 2 <0.99, 4<均方根误差 (RMSE%) <75, 0.01<平均绝对百分比误差 (MAPE) <0.97)。相比而言, Ba, Ca和Mg的观察值和模型计算值不太一致 (0.42<R 2 <0.70) 。利用最佳拟合模型生成了空间分布图, 提供水质分布模式信息。研究表明, 利用经验模型生成空间分布图可能成为监测酸性矿井 (山) 废水的一种简便, 有效方法。 Pocos estudios han evaluado la contaminación del agua asociada a la minería utilizando características espectrales. Utilizamos datos multiespectrales de alta resolución adquiridos por drones aéreos no tripulados combinados con datos químicos in situ para evaluar los parámetros de calidad del agua en 12 masas de agua relativamente pequeñas situadas en el complejo de Tharsis, una zona minera abandonada en la faja pirítica ibérica (SO de España). Las bandas espectrales de Micasense RedEdge-MX Dual y las combinaciones de bandas espectrales se utilizaron conjuntamente con los datos fisicoquímicos para estimar los parámetros de calidad del agua y desarrollar modelos empíricos fiables mediante análisis de regresión. Los parámetros fisicoquímicos incluyendo pH, ORP, EC, Al, Cu, Fe, Mn, S, Si y Zn fueron estimados con altos niveles de precisión (0.81<R 2 <0.99, 4 <RMSE%<75, 0.01<MAPE<0.97). En cambio, los valores observados y modelados para el Ba, el Ca y el Mg no coincidieron bien (0,42<R 2 <0,70). Los modelos mejor ajustados se utilizaron para generar mapas de distribución espacial, proporcionando información sobre los patrones de calidad del agua. Este estudio demostró que el uso de modelos empíricos para generar mapas de distribución espacial puede ser una forma efectiva y fácil de monitorear el drenaje ácido de minas. | Unmanned Aerial System-Based Multispectral Water Quality Monitoring in the Iberian Pyrite Belt (SW Spain) | 10.1007/s10230-021-00837-4 |
2022-03-01 | The Internet of Things (IoT) embodies the confluence of the virtual & physical world. IoT will play an important role in managing the managing depleting resource such as water, fuel, food, etc. However, to realize these applications enormous IoT devices will communicate with each other. This massive connectivity will directly or indirectly aid in Green House Gas emissions. Hence, to admissibly reduce this environmental impact of IoT, it must be greened in terms of energy consumption. Green IoT will reduce environmental exploitation by slashing carbon emission effectively and thus will help in achieving sustainability of the planet. This paper describes the journey of IoT to Green IoT. Along with this, the survey on recent Green-IoT techniques that will effectively help in reducing required energy consumption is presented. Along with this ability of unmanned aerial vehicle (UAV) technology to provide Green IoT and survey on recent energy-efficient UAV assisted communication is presented. In addition to this, a dual battery enabled Unmanned Aerial vehicle base station, an energy-efficient clustering algorithm, has also been proposed to prolong the battery life. | Green IoT: A Short Survey on Technical Evolution & Techniques | 10.1007/s11277-021-09142-3 |
2022-03-01 | Purpose This study aimed to identify factors that hinder 24-h patient discharge after laparoscopic Roux-en-Y gastric bypass (LRYGB) in a low-volume practice. Material and Methods Consecutive patients who fulfilled regional criteria and underwent primary LRYGB from 2018 to 2020 were retrospectively analyzed. Patients were discharged on the morning of the first postoperative day (POD1) after meeting the predefined criteria. The assessed outcome measures (POD1 vital signs, laboratory findings, pain scores and nausea/vomiting) and 30-day postoperative complications were compared between the early (stay ≤ 24 h) and delayed (>24 h) groups. Results For 107 patients who fulfilled the inclusion criteria, 48 (44.9%) were discharged within 24 h. There were no differences in the baseline demographics, except that the early group was more likely to have a previous abdominal operation (35.4% vs. 16.9%). Both groups had similar operation durations (89 min vs. 92 min), but the early group had a markedly shortened length of stay (23 (24–22) h vs. 27 (47–26) h). The POD1 parameters were the same between the groups, except that the delay group had a significantly higher visual analog scale score, with fewer patient scores of 0. Patients who were younger and female were more likely to need additional IV analgesics. No POD1 antiemesis was required throughout the study. There was no increase in the 30-day complications. Conclusion Patient discharge at 24 h post-LRYGB is feasible and safe in a low-volume practice. A more comprehensive pain relief strategy may be required before generalizing this approach. Graphical abstract | Factors that Hinder 24-Hour Discharge After Laparoscopic Roux-en-Y Gastric Bypass: a Retrospective Analysis at a Low-Volume Center | 10.1007/s11695-021-05813-z |
2022-03-01 | This paper proposes the Marine Predators Algorithm (MPA) as a new bio-inspired optimization algorithm to extract the parameters of three-photo voltaic models of solar cells. These models are three diode model (TDM), double diode model (DDM) and one-diode model (SDM). The MPA is dependent on the manner of a population of Marine Predators. This optimal strategy allows prey to use an optimal foraging strategy and allows predators to use an intelligent rate policy for encounters. The proposed MPA-based parameter estimation algorithm is tested at normal and low radiation operating conditions. The normal operating condition is employed with the 57 mm diameter commercial silicon solar cell (Case 1), while the Case 2 is based on a multi-crystalline silicon solar cell of area 7.7 cm 2 from Q6-1380 under low irradiance levels. The capability of MPA is validated for the three models compared with other competitive algorithms. Simulation results show that high closeness between the estimated and experimental records reflects the high capability of the MPA with more accurate parameters. The RMSE of 8.43854E−4, 7.59E−4 and 7.561E−4 are achieved for Case 1 by using SDM, DDM and TDM, respectively. While, the RMSE has the best levels of 1.61E−5, 1.46E−5, and 1.42E−5 in Case 2, respectively. Also, the MPA has competitive results compared with several optimization algorithms in the literature as sine cosine, particle swarm, salp swarm, grey wolf optimization algorithms. The proposed MPA has good convergence and robust statistical analysis for different operating conditions of low and high irradiance. | Effective PV Parameter Estimation Algorithm Based on Marine Predators Optimizer Considering Normal and Low Radiation Operating Conditions | 10.1007/s13369-021-06045-0 |
2022-03-01 | Aims/hypothesis Lifestyle modification and weight loss are cornerstones of type 2 diabetes management. However, carbohydrate restriction may have weight-independent beneficial effects on glycaemic control. This has been difficult to demonstrate because low-carbohydrate diets readily decrease body weight. We hypothesised that carbohydrate restriction enhances the beneficial metabolic effects of weight loss in type 2 diabetes. Methods This open-label, parallel RCT included adults with type 2 diabetes, HbA 1c 48–97 mmol/mol (6.5–11%), BMI >25 kg/m 2 , eGFR >30 ml min −1 [1.73 m] −2 and glucose-lowering therapy restricted to metformin or dipeptidyl peptidase-4 inhibitors. Participants were randomised by a third party and assigned to 6 weeks of energy restriction (all foods were provided) aiming at ~6% weight loss with either a carbohydrate-reduced high-protein diet (CRHP, percentage of total energy intake [E%]: CH30/P30/F40) or a conventional diabetes diet (CD, E%: CH50/P17/F33). Fasting blood samples, continuous glucose monitoring and magnetic resonance spectroscopy were used to assess glycaemic control, lipid metabolism and intrahepatic fat. Change in HbA 1c was the primary outcome; changes in circulating and intrahepatic triacylglycerol were secondary outcomes. Data were collected at Copenhagen University Hospital (Bispebjerg and Herlev). Results Seventy-two adults (CD 36, CRHP 36, all white, 38 male sex) with type 2 diabetes (mean duration 8 years, mean HbA 1c 57 mmol/mol [7.4%]) and mean BMI of 33 kg/m 2 were enrolled, of which 67 (CD 33, CRHP 34) completed the study. Body weight decreased by 5.8 kg (5.9%) in both groups after 6 weeks. Compared with the CD diet, the CRHP diet further reduced HbA 1c (mean [95% CI] −1.9 [−3.5, −0.3] mmol/mol [−0.18 (−0.32, −0.03)%], p = 0.018) and diurnal mean glucose (mean [95% CI] −0.8 [−1.2, −0.4] mmol/l, p < 0.001), stabilised glucose excursions by reducing glucose CV (mean [95% CI] −4.1 [−5.9, −2.2]%, p < 0.001), and augmented the reductions in fasting triacylglycerol concentration (by mean [95% CI] −18 [−29, −6]%, p < 0.01) and liver fat content (by mean [95% CI] −26 [−45, 0]%, p = 0.051). However, pancreatic fat content was decreased to a lesser extent by the CRHP than the CD diet (mean [95% CI] 33 [7, 65]%, p = 0.010). Fasting glucose, insulin, HOMA2-IR and cholesterol concentrations (total, LDL and HDL) were reduced significantly and similarly by both diets. Conclusions/interpretation Moderate carbohydrate restriction for 6 weeks modestly improved glycaemic control, and decreased circulating and intrahepatic triacylglycerol levels beyond the effects of weight loss itself compared with a CD diet in individuals with type 2 diabetes. Concurrent differences in protein and fat intakes, and the quality of dietary macronutrients, may have contributed to these results and should be explored in future studies. Trial registration ClinicalTrials.gov NCT03814694. Funding The study was funded by Arla Foods amba, The Danish Dairy Research Foundation, and Copenhagen University Hospital Bispebjerg Frederiksberg. Graphical abstract | Dietary carbohydrate restriction augments weight loss-induced improvements in glycaemic control and liver fat in individuals with type 2 diabetes: a randomised controlled trial | 10.1007/s00125-021-05628-8 |
2022-03-01 | Conventional therapies have aimed to try to help individuals suffering with dentine hypersensitivity (DH/DHS). A relatively new approach, laser therapy claims to be beneficial while having immediate and long-lasting effect. Therefore, our analysis aims to explore the immediate and 1-month efficacy of near-infrared laser (NIR) therapy in treating dentinal hypersensitivity. A systematic literature search conducted in databases, and analysis was undertaken utilizing a meta-analysis approach. Randomized controlled clinical trials comparing near-infrared lasers and placebo/no treatment in patients (> 18 years) were included. The risk of bias for included studies was assessed using Cochrane RoB tool (for randomized studies). Random effects meta-analyses model of standardized mean differences and 95% confidence intervals were performed using RevMan 5.4 software. A comprehensive electronic and manual search yielded a total of 1081 potential articles. Following the implementation of the inclusion and exclusion criteria, a total of 6 studies were included in the analysis. Near-infrared laser therapy led to statistical significant reduction in immediate and 1-month follow-up VAS (visual analog scale) scores compared to placebo/no treatment (p < 0.05). Statistical heterogeneity across the studies was high (I 2 -96%). The findings suggest that near-infrared laser therapy does have a significant immediate effect in reducing dentine hypersensitivity compared to placebo/no treatment. Furthermore, this effect is not diminished and endured at 1-month follow-up. | Efficacy of near infrared dental lasers on dentinal hypersensitivity: a meta-analysis of randomized controlled clinical trials
| 10.1007/s10103-021-03391-1 |
2022-03-01 | This paper describes an ultralow power consumption and ultra-small area all-digital phase-locked loop (ADPLL) for system-on-chip (SoC) applications. In the ADPLL, a dual-tuned digitally controlled oscillator (DCO) and dual-tuned locking algorithm are presented. The proposed DCO consists of a digital-to-analog converter (DAC) control array with a coarse-tuned stage and a fine-tuned stage. The different control codes for DAC array can be used as coarse-tuning code or fine-tuning code depending on the situation. The whole circuit is automatically place-and-routed (P&R) by a digital design flow. Fabricated in a 55-nm standard CMOS process, this ADPLL occupies only 34 $$\upmu $$ μ m $$ \times $$ × 24 $$\upmu $$ μ m core area, which to the best knowledge of the authors is the smallest phase-locked loop published so far. The experimental results indicate a fast locking process of the entire system. At the DCO frequency of 3 GHz, the power consumption is 112.32 $$\upmu $$ μ W with a 1.0-V supply voltage, and the root-mean-square jitter is 14.4 ps at 100 MHz pre-divider output frequency. | A 0.001-mm
$$^{2}$$
2
112.32-
$$\upmu $$
μ
W All-Digital PLL with Dual-Tuned DCO and Dual-Tuned Control Algorithm | 10.1007/s00034-021-01838-y |
2022-03-01 | The aim of this in vitro study was to evaluate the effects of low-level laser therapy (LLLT) at different energy intensities on proliferation and osteogenesis of periodontal ligament stem cells (PDLSCs). We designed one control group, without irradiation and four testing groups, treated with LLLT (Nd:YAG;1064 nm) at 2, 4, 6, and 8 J/cm 2 for human PDLSCs. Cell proliferation was measured using colony-forming unit fibroblast assay and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay. Osteogenic capacity of cells was determined by alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin Red S staining, and the gene levels of runt-related transcription factor 2 (Runx2), ALP, osteocalcin, and bone morphogenetic protein 2 (BMP2). The effects of LLLT on secretion of TNF-α and IL-1β in PDLSCs were measured by enzyme-linked immunosorbent assay. BMP/Smad pathway was measured through the expression of Smad1/5/8 phosphorylation (P-Smad1/5/8). LDN-193189, an inhibitor of the BMP/Smad pathway, was used to explore the underlying effects of BMP/Smad signaling on the process of LLLT regulating the proliferation and osteogenesis of PDLSCs. Our results demonstrated LLLT could promote the proliferation and osteogenesis of PDLSCs at 2–6 J/cm 2 and LLLT at 8 J/cm 2 significantly suppress osteogenic differentiation of PDLSCs. Moreover, LLLT stimulated the secretion of TNFα and IL-β1. Finally, we found the irradiation positively modulates the P-Smad1/5/8 level. When the cells were treated with LDN-193189, the proliferation and osteogenic effects of LLLT on PDLSCs were attenuated. In conclusion, LLLT may upregulate the proliferation and bone formation ability of PDLSCs via the BMP/Smad signaling. | Low-level laser irradiation enhances the proliferation and osteogenic differentiation of PDLSCs via BMP signaling | 10.1007/s10103-021-03338-6 |
2022-03-01 | The aim of the current study was to assess the impact of formulated high-fiber ingredient mix on the nutritional indices of selected Punjabi women suffering from metabolic syndrome. The developed mix contained about 323.7 Kcal energy, 14.5 ± 0.16 g protein, 12.9 ± 0.19 g dietary fiber, 2.1 ± 0.12 g fat and 61.7 g carbohydrate per 100 g. Post-intervention trial of 120 days, in intervention group, a significant reduction ( p ≤ 0.05) in weight from 68.46 ± 7.23 to 65.10 ± 7.23 kg was observed resulting in decreased body mass index from 27.89 ± 2.85 to 26.54 ± 2.84 kg/m 2 and 104.31 ± 9.91 to 101.41 ± 9.32 cm in hip circumference. Significant increase in hemoglobin by 5.9%, high-density lipoprotein (HDL) by 6.8% and decrease in cholesterol by 12.2%, low-density lipoprotein (LDL) by 18.2% and fasting blood glucose by 15.5% was recorded from pre- and post-test. The high protein and dietary fiber of developed ingredient mix had a significant inverse relation on body weight and biochemical parameters confirming that daily intake of multi-grain flours can be helpful in managing the body weight and can keep the blood lipid parameters in normal range. | Impact of High-Fiber Ingredient Mix on the Nutritional Indices of the Women Suffering from Metabolic Syndrome | 10.1007/s40011-021-01311-5 |
2022-03-01 | Genetic lineage tracing studies have shown that phenotypic switching of vascular smooth muscle cells (VSMCs) results in less-differentiated cells, including macrophage-like cells that lack traditional VSMC markers. This switching contributes to the formation of necrotic core in plaques and promotes atherosclerosis, which is important for plaque stability. Niclosamide, a commonly used anti-helminthic drug, has recently attracted attention as an anti-cancer drug that inhibits multiple signaling pathways. The expression of the S100A4 protein is upregulated in synthetic VSMCs and inhibited by niclosamide on metastatic progression in colon cancer. We aimed to test the effect of niclosamide on VSMC phenotype switching and plaque stability. To examine murine atherosclerosis, we induced experimental lesions by blood flow cessation in apolipoprotein E knockout mice fed a high-fat diet. Oral administration of niclosamide changed 4-week-old plaques to collagen-rich and less-necrotic core phenotypes and downregulated the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in vivo. In vitro analysis indicated that niclosamide reduced LOX-1 expression in VSMCs in a concentration-dependent and S100A4-independent manner. The inhibitory effect of niclosamide on LOX-1 and collagen type I was associated with the inactivation of the nuclear factor-κB signaling pathway. We demonstrated that the administration of niclosamide reduced LOX-1 expression and altered the composition of murine carotid plaques. Our results highlight the potential of niclosamide as an atheroprotective agent that enhances atherosclerotic plaque stability. | Niclosamide downregulates LOX-1 expression in mouse vascular smooth muscle cells and changes the composition of atherosclerotic plaques in ApoE−/− mice | 10.1007/s00380-021-01983-z |
2022-03-01 | A seismic network of ten three-component broadband seismographs was deployed in and around Hyderabad city during September–October 2020, which enabled us to record a rare lower-crustal cratonic earthquake of M w 3.9 that occurred on 25 July 2021 (23:31:01.1) at 35 km depth below the region about 140 km south of Hyderabad city. Utilizing broadband waveforms from this network, we model source parameters and moment tensor solution of this rare event using simultaneous inversion of S-wave spectra and ISOLA software, respectively. The average corner frequency, seismic moment, moment magnitude, stress drop, and source radius are 3.87 Hz, 7.14E + 14 N-m, 3.8, 3.92 MPa, and 229 m, respectively. The modelled mean crustal Q varies from 506 (at VKB) to 4136 (at NLG), with an average of 2182 ± 1178, suggesting lower crustal attenuation below the Hyderabad region. We perform a deviatoric moment tensor inversion of multiple point sources on the band-passed (0.04–0.1 Hz) displacement traces of the Hyderabad event. The best fit is obtained at 35 km centroid depth, with a moment magnitude of 3.9, and a normal dip-slip mechanism with a minor strike-slip component with strike of 169°, dip of 65°, and rake of −113°. The P-axis orients N42°E, which is parallel to the direction of the absolute plate motion direction of the Indian Plate, while the T-axis orients E–W. The occurrence of this earthquake could be attributed to the sudden movement on the almost-vertical plane in the viscous lower crust due to high fluid pore pressure resulting from the presence of CO 2 -rich mantle fluids. | Modelling of Moment Tensors and Source Parameters of the 25 July 2021 Rare Lower Crustal Hyderabad (India) Earthquake of Mw 3.9 | 10.1007/s00024-022-02973-6 |
2022-03-01 | Lower extremity deep venous thrombosis (LEDVT) is a venous reflux disorder caused by abnormal coagulation of blood. LEDVT can obstruct the lumen and LEDVT is the third vascular disease after cerebrovascular diseases and coronary artery diseases. miRNAs are associated with thrombosis, and miR-185 was reported to affect the proliferation and apoptosis of vascular endothelial cells by regulating receptor of advanced glycation end products (RAGE). However, no study has reported the effect of miR-185 on LEDVT. Here, we studied the effects of miR-185 on the PI3K/AKT and MAPK signaling pathways in the LEDVT cells. The results showed that miR-185 promotes cell proliferation through activating the PI3K/AKT and MAPK signaling pathways and then inhibits tissue factor and fibrin expression to reduce thrombosis. In short, our study provides new ideas and a theoretical basis for research on the prevention, diagnosis, and treatment of LEDVT. | Study on the Effect and Mechanism of miR-185 on Lower Extremity Deep Venous Thrombosis | 10.1007/s12033-021-00412-w |
2022-02-28 | Generally, low flow in rivers occur as a result of extended period of dryness which is likely attributed to drought. Drought is a natural occurrence as an outcome of reduction in precipitation in a region for a long time. Hence, low flow is a growing concern as there are possibilities of more reduced flows in rivers. However, reservoirs can be utilized to mitigate negative effects on the supply of water in dry periods and supply water for other purposes. This study aims at verifying how the low flow condition of Glomma River in Norway has been progressively sustained by hydropower reservoirs. Water Evaluation and Planning Systems (WEAP) software was used for modelling the natural streamflow condition of Glomma River, which is the longest river in Norway, using two unregulated sub-basins within the Glomma catchment. Findings from this study presents that the period between January and March are critical periods in Glomma River. Results show that the values the annual minimum low flow gotten from the three gauges suggest the flow after regulation has increased significantly as opposed to before regulation. The daily average flow is simulated by WEAP to be an average of 100 m 3 /s during the low flow periods and an average discharge of 350 m 3 /s during the summer. However, the result indicates that the flow in the summer has reduced by 80% in majority of the years. In addition, Nash Sutcliffe efficiency (NSE) for the two sub basins used for this study was 0.9 and 0.76, respectively. Also, the calculation of the coefficient of determination ( R 2 ) resulted in 0.85 and 0.78 respectively for the two sub basins. In particular, findings from this study presents evidence on the low flow condition in Glomma River prior to its regulation and how the regulation has sustained the flow. | Achieving sustainable low flow using hydropower reservoir for ecological water management in Glomma River Norway | 10.1007/s40899-022-00643-y |
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